Question
Find the multiplicative inverse of the following complex numbers: $1-\text{i}$

Answer

If $\text{z}=\text{x}+\text{iy}$ is a complex number, then the multiplicative inverse of z, denoted by $\text{z}^{-1}$ or $\frac{1}{\text{z}}$ is defined as $\text{z}^{-1}=\frac{1}{\text{z}}$ $=\frac{1}{\text{x}+\text{iy}}$ $=\frac{1}{\text{x}+\text{iy}}\times\frac{\text{x}-\text{iy}}{\text{x}-\text{iy}}$ $=\frac{\text{x}-\text{iy}}{\text{x}^2+\text{y}^2}$ $=\frac{\text{x}}{\text{x}^2+\text{y}^2}-\frac{\text{y}}{\text{x}^2+\text{y}^2}\text{i}$ Given $\text{z}=1-\text{i}$ $\therefore \ \text{z}^{-1}=\frac{1}{1^2+1^2}-\frac{(-1)}{1^2+1^2}\times\text{i}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Solve the following equations: $\tan3\text{x}+\tan\text{x}=2\tan2\text{x}$
If A = {1, 2, 3}, B = {4}, C = {5}, then verify that: $\text{A}\times(\text{B}\cap\text{C})=(\text{A}\times\text{B})\cap(\text{A}\times\text{C})$
Find the coordinates of the foci, the vertices, the length of major axis, the minor axis, the eccentricity and the length of the latus rectum of the ellipse.
$16x^2 + y^2 = 16$
Two plants A and B of a factory show following results about the number of workers and the wages paid to them:
  Plant A Plant B
No. of workers 5000 6000
Average monthly wages ₹ 2500 ₹ 2500
Variance of distribution of wages 81 100
In which plant A or B is there greater variability in individual wages?
If the sum of $n$ terms of an A.P. is $3 n^2+5 n$ and its $m^{\text {th }}$ term is 164 , find the value of $m$.
Evaluate the following limit: $\lim\limits_{\text{x}\rightarrow{1}}\frac{\text{x}^{15}-1}{\text{x}^{10}-1}$
There are four men and six women on the city councils. if one council member is selected for a committee at random, how likel6y is that it is a women?
The ratio of the sum of $m$ and $n$ terms of an A.P. is $m^2: n^2$ Show that the ratio of $m^{\text {th }}$ and $n^{\text {th }}$ term is $(2 m-1):(2 n-1)$.
If $(x + iy)^3 = u + iv$, then show that $\frac{u}{x} + \frac{v}{y} = 4({x^2} - {y^2})$
We know that the sum of the interior angles of a triangle is 180°. Show that the sums of the interior angles of polygons with 3, 4, 5, 6, ... sides form an arithmetic progression. Find the sum of the interior angles for a 21 sided polygon.