English

If Z1 and Z2 Are Two Complex Numbers Such that | Z 1 | = | Z 2 | and Arg(Z1) + Arg(Z2) = π Then Show that Z 1 = − ¯ Z 2 . - Mathematics

Advertisements
Advertisements

Question

If z1 and z2 are two complex numbers such that \[\left| z_1 \right| = \left| z_2 \right|\] and arg(z1) + arg(z2) = \[\pi\] then show that \[z_1 = - \bar{{z_2}}\].

Advertisements

Solution

Let θbe the arg(z1) and θbe the arg(z2).
It is given that

\[\left| z_1 \right| = \left| z_2 \right|\] and arg(z1) + arg(z2) = \[\pi\].

Since, z1 is a complex number.

\[z_1 = \left| z_1 \right|\left( \cos \theta_1 + i\sin \theta_1 \right)\]

\[ = \left| z_2 \right|\left[ \cos\left( \pi - \theta_2 \right) + i\sin\left( \pi - \theta_2 \right) \right]\]

\[ = \left| z_2 \right|\left[ - \cos\left( \theta_2 \right) + i\sin\left( \theta_2 \right) \right]\]

\[ = - \left| z_2 \right|\left[ \cos\left( \theta_2 \right) - i\sin\left( \theta_2 \right) \right]\]

\[ = - \bar{{z_2}}\]

Hence,  

\[z_1 = - \bar{{z_2}}\].

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.4 [Page 57]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.4 | Q 4 | Page 57

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

If a + ib  = `(x + i)^2/(2x^2 + 1)` prove that a2 + b= `(x^2 + 1)^2/(2x + 1)^2`


Evaluate the following:

i457


Express the following complex number in the standard form a + i b:

\[\frac{(1 - i )^3}{1 - i^3}\]


Find the real value of x and y, if

\[(3x - 2iy)(2 + i )^2 = 10(1 + i)\]


If \[z_1 = 2 - i, z_2 = - 2 + i,\] find 

Re \[\left( \frac{z_1 z_2}{z_1} \right)\]


If \[z_1 = 2 - i, z_2 = - 2 + i,\] find 

Im `(1/(z_1overlinez_1))`


Find the least positive integral value of n for which  \[\left( \frac{1 + i}{1 - i} \right)^n\] is real.


If \[\left( \frac{1 + i}{1 - i} \right)^3 - \left( \frac{1 - i}{1 + i} \right)^3 = x + iy\] find (xy).


If \[\frac{\left( 1 + i \right)^2}{2 - i} = x + iy\]  find x + y.


Evaluate the following:

\[x^4 + 4 x^3 + 6 x^2 + 4x + 9, \text { when } x = - 1 + i\sqrt{2}\]


If \[\left( 1 + i \right)z = \left( 1 - i \right) \bar{z}\],then show that \[z = - i \bar{z}\].


Write (i25)3 in polar form.


Write the value of \[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}}\] .


Write the argument of −i.


Find z, if \[\left| z \right| = 4 \text { and }\arg(z) = \frac{5\pi}{6} .\]


Find the real value of a for which \[3 i^3 - 2a i^2 + (1 - a)i + 5\] is real.


If \[\left| z \right| = 2 \text { and } \arg\left( z \right) = \frac{\pi}{4}\],find z.


If `(3+2i sintheta)/(1-2 i sin theta)`is a real number and 0 < θ < 2π, then θ =


If a = cos θ + i sin θ, then \[\frac{1 + a}{1 - a} =\]


\[\text { If } z = \frac{1}{(1 - i)(2 + 3i)}, \text { than } \left| z \right| =\]


The complex number z which satisfies the condition \[\left| \frac{i + z}{i - z} \right| = 1\] lies on


Which of the following is correct for any two complex numbers z1 and z2?

 


Find a and b if a + 2b + 2ai = 4 + 6i


Find a and b if `1/("a" + "ib")` = 3 – 2i


Express the following in the form of a + ib, a, b ∈ R, i = `sqrt(−1)`. State the values of a and b:

(1 + i)(1 − i)−1 


Express the following in the form of a + ib, a, b∈R i = `sqrt(−1)`. State the values of a and b:

`((2 + "i"))/((3 - "i")(1 + 2"i"))`


Express the following in the form of a + ib, a, b∈R i = `sqrt(−1)`. State the values of a and b:

`((1 + "i")/(1 - "i"))^2`


Express the following in the form of a + ib, a, b ∈ R i = `sqrt(−1)`. State the values of a and b:

`(2 + sqrt(-3))/(4 + sqrt(-3))`


Express the following in the form of a + ib, a, b ∈ R, i = `sqrt(−1)`. State the values of a and b:

`(4"i"^8 - 3"i"^9 + 3)/(3"i"^11 - 4"i"^10 - 2)`


Evaluate the following : `1/"i"^58`


If z1 = 3 – 2i and z2 = –1 + 3i, then Im(z1z2) = ______.


If z1 and z2 both satisfy `z + barz = 2|z - 1|` arg`(z_1 - z_2) = pi/4`, then find `"Im" (z_1 + z_2)`.


State true or false for the following:

If a complex number coincides with its conjugate, then the number must lie on imaginary axis.


If a = cosθ + isinθ, find the value of `(1 + "a")/(1 - "a")`.


Find the value of `(i^(592) + i^(590) + i^(588) + i^(586) + i^(584))/(i^(582) + i^(580) + i^(578) + i^(576) + i^(574))`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×