Finding z with a complex number (z & conjugate z)












3














I have the following question and cannot seem to overcome how to mix z and conjugate z together.




Find the value of $z in Bbb C$ that verifies the equation:
$$3z+ibar z=4+i$$




For other operations that didn't include mixing $z$ and $bar z$, I was able to manage by "isolating" $z$ on one side of the equation and finding the real and imaginary parts of the complex numbers (sorry if I'm not using the right terms, it's my first linear algebra course)



I tried with wolfram and it didn't really help.



PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.










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Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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    3














    I have the following question and cannot seem to overcome how to mix z and conjugate z together.




    Find the value of $z in Bbb C$ that verifies the equation:
    $$3z+ibar z=4+i$$




    For other operations that didn't include mixing $z$ and $bar z$, I was able to manage by "isolating" $z$ on one side of the equation and finding the real and imaginary parts of the complex numbers (sorry if I'm not using the right terms, it's my first linear algebra course)



    I tried with wolfram and it didn't really help.



    PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.










    share|cite|improve this question









    New contributor




    Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      3












      3








      3







      I have the following question and cannot seem to overcome how to mix z and conjugate z together.




      Find the value of $z in Bbb C$ that verifies the equation:
      $$3z+ibar z=4+i$$




      For other operations that didn't include mixing $z$ and $bar z$, I was able to manage by "isolating" $z$ on one side of the equation and finding the real and imaginary parts of the complex numbers (sorry if I'm not using the right terms, it's my first linear algebra course)



      I tried with wolfram and it didn't really help.



      PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.










      share|cite|improve this question









      New contributor




      Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I have the following question and cannot seem to overcome how to mix z and conjugate z together.




      Find the value of $z in Bbb C$ that verifies the equation:
      $$3z+ibar z=4+i$$




      For other operations that didn't include mixing $z$ and $bar z$, I was able to manage by "isolating" $z$ on one side of the equation and finding the real and imaginary parts of the complex numbers (sorry if I'm not using the right terms, it's my first linear algebra course)



      I tried with wolfram and it didn't really help.



      PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.







      linear-algebra complex-numbers






      share|cite|improve this question









      New contributor




      Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|cite|improve this question









      New contributor




      Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|cite|improve this question




      share|cite|improve this question








      edited 1 hour ago









      Eevee Trainer

      3,860428




      3,860428






      New contributor




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      Check out our Code of Conduct.









      asked 1 hour ago









      Laura Salas

      161




      161




      New contributor




      Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Laura Salas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






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      Check out our Code of Conduct.






















          3 Answers
          3






          active

          oldest

          votes


















          2














          Hint:



          Let $z = x + iy$, for $x,y in mathbb{R}$. Consequently, $bar{z} = x - iy$.



          Make these substitutions into your equation and isolate all of the $x$ and $y$ terms on one side, trying to make it "look" like a number in that form above (I really don't know how else to describe it, my example below will be more illustrative).



          Equate the real and imaginary parts to get a system of equations in two variables ($x,y$) which you can solve get your solution.





          Similar Exercise To Show What I Mean:



          Let's solve for $z$ with



          $$iz + 2bar{z} = 1 + 2i$$



          Then, making our substitutions...



          $$begin{align}
          iz + 2bar{z} &= i(x + iy) + 2(x - iy) \
          &= ix + i^2 y + 2x - 2iy \
          &= ix - y + 2x - 2iy \
          &= (2x - y) + i(x - 2y) \
          end{align}$$



          Thus,



          $$ (2x - y) + i(x - 2y) = 1 + 2i$$



          The real part of our left side is $2x-y$ and the imaginary part is $x - 2y$. On the right, the real and imaginary parts are $1$ and $2$ respectively.



          Then, we get a system of equations by equating real and imaginary parts!



          $$begin{align}
          2x - y &= 1\
          x - 2y &= 2\
          end{align}$$



          You can quickly show with basic algebra that $y = -1, x = 0$.



          Our solution is a $z$ of the form $z = x + iy$. Thus, $z = 0 + i(-1) = -i$.





          One Final Tidbit:




          PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.




          This forum doesn't mind helping you with homework, so long as you show you make a reasonable effort or at least have a clear understanding of the material. However, the goal is also to help you learn, so people tend to prefer nudges in the right direction if the context allows it, as opposed to just handing you the solution. (Imagine how people would abuse the site for homework if every just gave the answers. Not good, and not what math is about, you get me?)






          share|cite|improve this answer





























            2














            If $z=a+bi$ then $bar z=a-bi$



            So you are solving:
            $$3(a+bi)+i(a-bi)=4+i$$
            $$to (3a+b)+(a+3b)i=4+i$$
            Hence solve the simultaneous equations:



            $$3a+b=4$$
            $$a+3b=1$$






            share|cite|improve this answer





























              0














              Let $a$ and $b$ be the real and imaginary parts of $z$. The equation becomes $$(3a+ib)+i(a-ib)=4+i$$



              Equating real and imaginary parts you get $3a+b= 4$ and $3b+a=1$. Now you should be able to discover that $a=frac {11} 8$ and $b =-frac 1 8$, so $z=frac {11} 8-ifrac 1 8$.






              share|cite|improve this answer



















              • 1




                It’s $3a + 3ib$ in the first bracket of your first equation.
                – Live Free or π Hard
                1 hour ago











              Your Answer





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              3 Answers
              3






              active

              oldest

              votes








              3 Answers
              3






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              2














              Hint:



              Let $z = x + iy$, for $x,y in mathbb{R}$. Consequently, $bar{z} = x - iy$.



              Make these substitutions into your equation and isolate all of the $x$ and $y$ terms on one side, trying to make it "look" like a number in that form above (I really don't know how else to describe it, my example below will be more illustrative).



              Equate the real and imaginary parts to get a system of equations in two variables ($x,y$) which you can solve get your solution.





              Similar Exercise To Show What I Mean:



              Let's solve for $z$ with



              $$iz + 2bar{z} = 1 + 2i$$



              Then, making our substitutions...



              $$begin{align}
              iz + 2bar{z} &= i(x + iy) + 2(x - iy) \
              &= ix + i^2 y + 2x - 2iy \
              &= ix - y + 2x - 2iy \
              &= (2x - y) + i(x - 2y) \
              end{align}$$



              Thus,



              $$ (2x - y) + i(x - 2y) = 1 + 2i$$



              The real part of our left side is $2x-y$ and the imaginary part is $x - 2y$. On the right, the real and imaginary parts are $1$ and $2$ respectively.



              Then, we get a system of equations by equating real and imaginary parts!



              $$begin{align}
              2x - y &= 1\
              x - 2y &= 2\
              end{align}$$



              You can quickly show with basic algebra that $y = -1, x = 0$.



              Our solution is a $z$ of the form $z = x + iy$. Thus, $z = 0 + i(-1) = -i$.





              One Final Tidbit:




              PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.




              This forum doesn't mind helping you with homework, so long as you show you make a reasonable effort or at least have a clear understanding of the material. However, the goal is also to help you learn, so people tend to prefer nudges in the right direction if the context allows it, as opposed to just handing you the solution. (Imagine how people would abuse the site for homework if every just gave the answers. Not good, and not what math is about, you get me?)






              share|cite|improve this answer


























                2














                Hint:



                Let $z = x + iy$, for $x,y in mathbb{R}$. Consequently, $bar{z} = x - iy$.



                Make these substitutions into your equation and isolate all of the $x$ and $y$ terms on one side, trying to make it "look" like a number in that form above (I really don't know how else to describe it, my example below will be more illustrative).



                Equate the real and imaginary parts to get a system of equations in two variables ($x,y$) which you can solve get your solution.





                Similar Exercise To Show What I Mean:



                Let's solve for $z$ with



                $$iz + 2bar{z} = 1 + 2i$$



                Then, making our substitutions...



                $$begin{align}
                iz + 2bar{z} &= i(x + iy) + 2(x - iy) \
                &= ix + i^2 y + 2x - 2iy \
                &= ix - y + 2x - 2iy \
                &= (2x - y) + i(x - 2y) \
                end{align}$$



                Thus,



                $$ (2x - y) + i(x - 2y) = 1 + 2i$$



                The real part of our left side is $2x-y$ and the imaginary part is $x - 2y$. On the right, the real and imaginary parts are $1$ and $2$ respectively.



                Then, we get a system of equations by equating real and imaginary parts!



                $$begin{align}
                2x - y &= 1\
                x - 2y &= 2\
                end{align}$$



                You can quickly show with basic algebra that $y = -1, x = 0$.



                Our solution is a $z$ of the form $z = x + iy$. Thus, $z = 0 + i(-1) = -i$.





                One Final Tidbit:




                PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.




                This forum doesn't mind helping you with homework, so long as you show you make a reasonable effort or at least have a clear understanding of the material. However, the goal is also to help you learn, so people tend to prefer nudges in the right direction if the context allows it, as opposed to just handing you the solution. (Imagine how people would abuse the site for homework if every just gave the answers. Not good, and not what math is about, you get me?)






                share|cite|improve this answer
























                  2












                  2








                  2






                  Hint:



                  Let $z = x + iy$, for $x,y in mathbb{R}$. Consequently, $bar{z} = x - iy$.



                  Make these substitutions into your equation and isolate all of the $x$ and $y$ terms on one side, trying to make it "look" like a number in that form above (I really don't know how else to describe it, my example below will be more illustrative).



                  Equate the real and imaginary parts to get a system of equations in two variables ($x,y$) which you can solve get your solution.





                  Similar Exercise To Show What I Mean:



                  Let's solve for $z$ with



                  $$iz + 2bar{z} = 1 + 2i$$



                  Then, making our substitutions...



                  $$begin{align}
                  iz + 2bar{z} &= i(x + iy) + 2(x - iy) \
                  &= ix + i^2 y + 2x - 2iy \
                  &= ix - y + 2x - 2iy \
                  &= (2x - y) + i(x - 2y) \
                  end{align}$$



                  Thus,



                  $$ (2x - y) + i(x - 2y) = 1 + 2i$$



                  The real part of our left side is $2x-y$ and the imaginary part is $x - 2y$. On the right, the real and imaginary parts are $1$ and $2$ respectively.



                  Then, we get a system of equations by equating real and imaginary parts!



                  $$begin{align}
                  2x - y &= 1\
                  x - 2y &= 2\
                  end{align}$$



                  You can quickly show with basic algebra that $y = -1, x = 0$.



                  Our solution is a $z$ of the form $z = x + iy$. Thus, $z = 0 + i(-1) = -i$.





                  One Final Tidbit:




                  PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.




                  This forum doesn't mind helping you with homework, so long as you show you make a reasonable effort or at least have a clear understanding of the material. However, the goal is also to help you learn, so people tend to prefer nudges in the right direction if the context allows it, as opposed to just handing you the solution. (Imagine how people would abuse the site for homework if every just gave the answers. Not good, and not what math is about, you get me?)






                  share|cite|improve this answer












                  Hint:



                  Let $z = x + iy$, for $x,y in mathbb{R}$. Consequently, $bar{z} = x - iy$.



                  Make these substitutions into your equation and isolate all of the $x$ and $y$ terms on one side, trying to make it "look" like a number in that form above (I really don't know how else to describe it, my example below will be more illustrative).



                  Equate the real and imaginary parts to get a system of equations in two variables ($x,y$) which you can solve get your solution.





                  Similar Exercise To Show What I Mean:



                  Let's solve for $z$ with



                  $$iz + 2bar{z} = 1 + 2i$$



                  Then, making our substitutions...



                  $$begin{align}
                  iz + 2bar{z} &= i(x + iy) + 2(x - iy) \
                  &= ix + i^2 y + 2x - 2iy \
                  &= ix - y + 2x - 2iy \
                  &= (2x - y) + i(x - 2y) \
                  end{align}$$



                  Thus,



                  $$ (2x - y) + i(x - 2y) = 1 + 2i$$



                  The real part of our left side is $2x-y$ and the imaginary part is $x - 2y$. On the right, the real and imaginary parts are $1$ and $2$ respectively.



                  Then, we get a system of equations by equating real and imaginary parts!



                  $$begin{align}
                  2x - y &= 1\
                  x - 2y &= 2\
                  end{align}$$



                  You can quickly show with basic algebra that $y = -1, x = 0$.



                  Our solution is a $z$ of the form $z = x + iy$. Thus, $z = 0 + i(-1) = -i$.





                  One Final Tidbit:




                  PS: I'm new to this forum but if it's like other math forums where they send you to hell if you ask for "help with your homework", this "homework" I'm doing is on my own since my semester is over and I just wanted to explore other subjects in the book that weren't covered in class.




                  This forum doesn't mind helping you with homework, so long as you show you make a reasonable effort or at least have a clear understanding of the material. However, the goal is also to help you learn, so people tend to prefer nudges in the right direction if the context allows it, as opposed to just handing you the solution. (Imagine how people would abuse the site for homework if every just gave the answers. Not good, and not what math is about, you get me?)







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered 1 hour ago









                  Eevee Trainer

                  3,860428




                  3,860428























                      2














                      If $z=a+bi$ then $bar z=a-bi$



                      So you are solving:
                      $$3(a+bi)+i(a-bi)=4+i$$
                      $$to (3a+b)+(a+3b)i=4+i$$
                      Hence solve the simultaneous equations:



                      $$3a+b=4$$
                      $$a+3b=1$$






                      share|cite|improve this answer


























                        2














                        If $z=a+bi$ then $bar z=a-bi$



                        So you are solving:
                        $$3(a+bi)+i(a-bi)=4+i$$
                        $$to (3a+b)+(a+3b)i=4+i$$
                        Hence solve the simultaneous equations:



                        $$3a+b=4$$
                        $$a+3b=1$$






                        share|cite|improve this answer
























                          2












                          2








                          2






                          If $z=a+bi$ then $bar z=a-bi$



                          So you are solving:
                          $$3(a+bi)+i(a-bi)=4+i$$
                          $$to (3a+b)+(a+3b)i=4+i$$
                          Hence solve the simultaneous equations:



                          $$3a+b=4$$
                          $$a+3b=1$$






                          share|cite|improve this answer












                          If $z=a+bi$ then $bar z=a-bi$



                          So you are solving:
                          $$3(a+bi)+i(a-bi)=4+i$$
                          $$to (3a+b)+(a+3b)i=4+i$$
                          Hence solve the simultaneous equations:



                          $$3a+b=4$$
                          $$a+3b=1$$







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered 1 hour ago









                          Rhys Hughes

                          4,7531327




                          4,7531327























                              0














                              Let $a$ and $b$ be the real and imaginary parts of $z$. The equation becomes $$(3a+ib)+i(a-ib)=4+i$$



                              Equating real and imaginary parts you get $3a+b= 4$ and $3b+a=1$. Now you should be able to discover that $a=frac {11} 8$ and $b =-frac 1 8$, so $z=frac {11} 8-ifrac 1 8$.






                              share|cite|improve this answer



















                              • 1




                                It’s $3a + 3ib$ in the first bracket of your first equation.
                                – Live Free or π Hard
                                1 hour ago
















                              0














                              Let $a$ and $b$ be the real and imaginary parts of $z$. The equation becomes $$(3a+ib)+i(a-ib)=4+i$$



                              Equating real and imaginary parts you get $3a+b= 4$ and $3b+a=1$. Now you should be able to discover that $a=frac {11} 8$ and $b =-frac 1 8$, so $z=frac {11} 8-ifrac 1 8$.






                              share|cite|improve this answer



















                              • 1




                                It’s $3a + 3ib$ in the first bracket of your first equation.
                                – Live Free or π Hard
                                1 hour ago














                              0












                              0








                              0






                              Let $a$ and $b$ be the real and imaginary parts of $z$. The equation becomes $$(3a+ib)+i(a-ib)=4+i$$



                              Equating real and imaginary parts you get $3a+b= 4$ and $3b+a=1$. Now you should be able to discover that $a=frac {11} 8$ and $b =-frac 1 8$, so $z=frac {11} 8-ifrac 1 8$.






                              share|cite|improve this answer














                              Let $a$ and $b$ be the real and imaginary parts of $z$. The equation becomes $$(3a+ib)+i(a-ib)=4+i$$



                              Equating real and imaginary parts you get $3a+b= 4$ and $3b+a=1$. Now you should be able to discover that $a=frac {11} 8$ and $b =-frac 1 8$, so $z=frac {11} 8-ifrac 1 8$.







                              share|cite|improve this answer














                              share|cite|improve this answer



                              share|cite|improve this answer








                              edited 1 hour ago









                              Eevee Trainer

                              3,860428




                              3,860428










                              answered 1 hour ago









                              Kavi Rama Murthy

                              49.4k31854




                              49.4k31854








                              • 1




                                It’s $3a + 3ib$ in the first bracket of your first equation.
                                – Live Free or π Hard
                                1 hour ago














                              • 1




                                It’s $3a + 3ib$ in the first bracket of your first equation.
                                – Live Free or π Hard
                                1 hour ago








                              1




                              1




                              It’s $3a + 3ib$ in the first bracket of your first equation.
                              – Live Free or π Hard
                              1 hour ago




                              It’s $3a + 3ib$ in the first bracket of your first equation.
                              – Live Free or π Hard
                              1 hour ago










                              Laura Salas is a new contributor. Be nice, and check out our Code of Conduct.










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                              Laura Salas is a new contributor. Be nice, and check out our Code of Conduct.












                              Laura Salas is a new contributor. Be nice, and check out our Code of Conduct.
















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