English

The Argument of 1 − I 1 + I is - Mathematics

Advertisements
Advertisements

Question

The argument of \[\frac{1 - i}{1 + i}\] is

Options

  • \[- \frac{\pi}{2}\]

  • \[\frac{\pi}{2}\]

  • \[\frac{3\pi}{2}\]

  • \[\frac{5\pi}{2}\]

MCQ
Advertisements

Solution

\[- \frac{\pi}{2}\]

\[\text { Let } z = \frac{1 - i}{1 + i}\]

\[ \Rightarrow z=\frac{1 - i}{1 + i}\times\frac{1 - i}{1 - i}\]

\[ \Rightarrow z=\frac{1 + i^2 - 2i}{1 - i^2}\]

\[ \Rightarrow z = \frac{1 - 1 - 2i}{1 + 1}\]

\[ \Rightarrow z=\frac{- 2i}{2}\]

\[ \Rightarrow z= - i\]

\[\text { Since, z lies on negative direction of imaginary axis } . \]

\[\text { Therefore, } \arg (z) = \frac{- \pi}{2}\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.6 [Page 66]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.6 | Q 31 | Page 66

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Express the given complex number in the form a + ib: i9 + i19


Evaluate the following:

(ii) i528


Evaluate the following:

 \[\frac{1}{i^{58}}\]


Evaluate the following:

\[\left( i^{41} + \frac{1}{i^{257}} \right)^9\]


Evaluate the following:

\[i^{49} + i^{68} + i^{89} + i^{110}\]


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

\[\frac{3 + 2i}{- 2 + i}\]


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

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


Find the real value of x and y, if

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


Find the real value of x and y, if `((1+i)x-2i)/(3+i) + ((2-3i)y+i)/(3-i) = i, xy ∈ R, i = sqrt-1`


Find the real values of θ for which the complex number \[\frac{1 + i cos\theta}{1 - 2i cos\theta}\]  is purely real.


Evaluate the following:

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


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


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


What is the smallest positive integer n for which \[\left( 1 + i \right)^{2n} = \left( 1 - i \right)^{2n}\] ?


Find the number of solutions of \[z^2 + \left| z \right|^2 = 0\].


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


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

\[\frac{1 - i}{\cos\frac{\pi}{3} + i\sin\frac{\pi}{3}}\]


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


If π < θ < 2π and z = 1 + cos θ + i sin θ, then write the value of \[\left| z \right|\] .


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


Find the principal argument of \[\left( 1 + i\sqrt{3} \right)^2\] .


If \[\left| z + 4 \right| \leq 3\], then find the greatest and least values of \[\left| z + 1 \right|\].


The polar form of (i25)3 is


The least positive integer n such that \[\left( \frac{2i}{1 + i} \right)^n\] is a positive integer, is.

 

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


The value of \[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}} - 1\] is 


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


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`


Evaluate the following : i403 


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


Evaluate the following : i30 + i40 + i50 + i60 


If `((1 + "i"sqrt3)/(1 - "i"sqrt3))^"n"` is an integer, then n is ______.


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


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


Match the statements of Column A and Column B.

Column A Column B
(a) The polar form of `i + sqrt(3)` is  (i) Perpendicular bisector of
segment joining (–2, 0)
and (2, 0).
(b) The amplitude of `-1 + sqrt(-3)` is  (ii) On or outside the circle
having centre at (0, –4)
and radius 3.
(c) If |z + 2| = |z − 2|, then locus of z is (iii) `(2pi)/3`
(d) If |z + 2i| = |z − 2i|, then locus of z is (iv) Perpendicular bisector of
segment joining (0, –2) and (0, 2).
(e) Region represented by |z + 4i| ≥ 3 is  (v) `2(cos  pi/6 + i sin  pi/6)`
(f) Region represented by |z + 4| ≤ 3 is  (vi) On or inside the circle having
centre (–4, 0) and radius 3 units.
(g) Conjugate of `(1 + 2i)/(1 - i)` lies in (vii) First quadrant
(h) Reciprocal of 1 – i lies in (viii) Third quadrant

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×