English

Find the Multiplicative Inverse of the Following Complex Number:1 − I

Advertisements
Advertisements

Question

Find the multiplicative inverse of the following complex number:

1 − i

Advertisements

Solution

\[\text{ Let} z = 1 - i . \text { Then} , \]

\[\frac{1}{z} = \frac{1}{1 - i}\]

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

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

\[ = \frac{1}{2}\left( 1 + i \right)\]

\[ = \frac{1}{2} + \frac{1}{2}i\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Complex Numbers - Exercise 13.2 [Page 32]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.2 | Q 4.1 | Page 32

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Express the given complex number in the form a + ib: `(5i) (- 3/5 i)`


Express the given complex number in the form a + ib: i–39


Express the given complex number in the form a + ib: 3(7 + i7) + i(7 + i7)


Express the given complex number in the form a + ib: `(-2 - 1/3 i)^3`


Evaluate: `[i^18 + (1/i)^25]^3`


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


Evaluate the following:

 \[i^{30} + i^{40} + i^{60}\]


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:

\[\frac{1 - i}{1 + i}\]


If \[z_1 = 2 - i, z_2 = 1 + i,\text {  find } \left| \frac{z_1 + z_2 + 1}{z_1 - z_2 + i} \right|\]


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


Solve the equation \[\left| z \right| = z + 1 + 2i\].


If z1, z2, z3 are complex numbers such that \[\left| z_1 \right| = \left| z_2 \right| = \left| z_3 \right| = \left| \frac{1}{z_1} + \frac{1}{z_2} + \frac{1}{z_3} \right| = 1\] then find the value of \[\left| z_1 + z_2 + z_3 \right|\] .


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


For any two complex numbers z1 and z2 and any two real numbers a, b, find the value of \[\left| a z_1 - b z_2 \right|^2 + \left| a z_2 + b z_1 \right|^2\].


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


If\[z = \cos\frac{\pi}{4} + i \sin\frac{\pi}{6}\], then


The polar form of (i25)3 is


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


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

 

If z is a non-zero complex number, then \[\left| \frac{\left| z \right|^2}{zz} \right|\] is equal to


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


\[\text { If  }z = 1 - \text { cos }\theta + i \text { sin }\theta, \text { then } \left| z \right| =\]


The amplitude of \[\frac{1}{i}\] is equal to


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

 


Simplify : `sqrt(-16) + 3sqrt(-25) + sqrt(-36) - sqrt(-625)`


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:

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


Evaluate the following : i–888 


Show that 1 + i10 + i20 + i30 is a real number


Answer the following:

Show that z = `5/((1 - "i")(2 - "i")(3 - "i"))` is purely imaginary number.


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


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)`.


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

If w is a complex cube-root of unity, then prove the following

(w2 + w − 1)3 = −8


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×