English

Find Z, If | Z | = 4 and Arg ( Z ) = 5 π 6 .

Advertisements
Advertisements

Question

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

Advertisements

Solution

We know that,

\[z = \left| z \right|\left\{ \cos\left[ \arg(z) \right] + i\sin\left[ \arg(z) \right] \right\}\]

\[ \Rightarrow z = 4\left( \cos\frac{5\pi}{6} + i\sin\frac{5\pi}{6} \right)\]

\[ = 4\left( - \cos\frac{\pi}{6} + i\sin\frac{\pi}{6} \right)\]

\[ = 4\left( - \frac{\sqrt{3}}{2} + \frac{1}{2}i \right)\]

\[ = - 2\sqrt{3} + 2i\]

Thus, 

\[z = - 2\sqrt{3} + 2i\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.5 [Page 62]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.5 | Q 12 | Page 62

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Express the given complex number in the form a + ib: `(1/5 + i 2/5) - (4 + i 5/2)`


Let z1 = 2 – i, z2 = –2 + i. Find `"Im"(1/(z_1barz_1))`


Evaluate the following:

 \[\frac{1}{i^{58}}\]


Evaluate the following:

\[( i^{77} + i^{70} + i^{87} + i^{414} )^3\]


Find the value of the following expression:

i30 + i80 + i120


Find the value of the following expression:

i + i2 + i3 + i4


Find the value of the following expression:

i5 + i10 + i15


Find the value of the following expression:

1+ i2 + i4 + i6 + i8 + ... + i20


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

\[\frac{1}{(2 + i )^2}\]


Express the following complex number in the standard form a + ib:

\[\frac{(2 + i )^3}{2 + 3i}\]


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

\[(1 + 2i )^{- 3}\]


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

\[\frac{3 - 4i}{(4 - 2i)(1 + i)}\]


Find the real value of x and y, if

\[(x + iy)(2 - 3i) = 4 + i\]


If \[x + iy = \frac{a + ib}{a - ib}\] prove that x2 + y2 = 1.


If \[a = \cos\theta + i\sin\theta\], find the value of \[\frac{1 + a}{1 - a}\].


Evaluate the following:

\[2 x^3 + 2 x^2 - 7x + 72, \text { when } x = \frac{3 - 5i}{2}\]


Evaluate the following:

\[x^4 - 4 x^3 + 4 x^2 + 8x + 44,\text {  when } x = 3 + 2i\]


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


Solve the system of equations \[\text { Re }\left( z^2 \right) = 0, \left| z \right| = 2\].


If \[\frac{z - 1}{z + 1}\] is purely imaginary number (\[z \neq - 1\]), find the value of \[\left| z \right|\].


Express the following complex in the form r(cos θ + i sin θ):

1 − sin α + i cos α


Express \[\sin\frac{\pi}{5} + i\left( 1 - \cos\frac{\pi}{5} \right)\] in polar form.


If n is any positive integer, write the value of \[\frac{i^{4n + 1} - i^{4n - 1}}{2}\].


Write 1 − i in polar form.


If \[\left| z - 5i \right| = \left| z + 5i \right|\] , then find the locus of z.


Write the sum of the series \[i + i^2 + i^3 + . . . .\] upto 1000 terms.


The polar form of (i25)3 is


If \[z = \frac{1 + 2i}{1 - (1 - i )^2}\], then arg (z) equal


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


If \[x + iy = \frac{3 + 5i}{7 - 6i},\]  then y =


The amplitude of \[\frac{1 + i\sqrt{3}}{\sqrt{3} + i}\] is 


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"))^2`


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

`(3 + 2"i")/(2 - 5"i") + (3 -2"i")/(2 + 5"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)−3 


Evaluate the following : i403 


Show that `(-1+sqrt3i)^3` is a real number.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×