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RD Sharma solutions for Mathematics [English] Class 11 chapter 13 - Complex Numbers [Latest edition]

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Solutions for Chapter 13: Complex Numbers

Below listed, you can find solutions for Chapter 13 of CBSE, Karnataka Board PUC RD Sharma for Mathematics [English] Class 11.


Exercise 13.1Exercise 13.2Exercise 13.3Exercise 13.4Exercise 13.5Exercise 13.6
Exercise 13.1 [Pages 3 - 4]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.1 [Pages 3 - 4]

1.1Page 3

Evaluate the following:

i457

1.2Page 3

Evaluate the following:

(ii) i528

1.3Page 3

Evaluate the following:

 \[\frac{1}{i^{58}}\]

1.4Page 3

Evaluate the following:

\[i^{37} + \frac{1}{i^{67}}\].

1.5Page 3

Evaluate the following:

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

1.6Page 3

Evaluate the following:

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

1.7Page 13

Evaluate the following:

 \[i^{30} + i^{40} + i^{60}\]

1.8Page 3

Evaluate the following:

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

2Page 4

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

3.1Page 4

Find the value of the following expression:

i49 + i68 + i89 + i110

3.2Page 4

Find the value of the following expression:

i30 + i80 + i120

3.3Page 4

Find the value of the following expression:

i + i2 + i3 + i4

3.4Page 4

Find the value of the following expression:

i5 + i10 + i15

3.5Page 4

Find the value of the following expression:

\[\frac{i^{592} + i^{590} + i^{588} + i^{586} + i^{584}}{i^{582} + i^{580} + i^{578} + i^{576} + i^{574}}\]

3.6Page 4

Find the value of the following expression:

1+ i2 + i4 + i6 + i8 + ... + i20

3.7Page 4

Find the value of the following expression:

(1 + i)6 + (1 − i)3

Exercise 13.2 [Pages 31 - 33]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.2 [Pages 31 - 33]

1.01Page 31

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

\[(1 + i)(1 + 2i)\]

1.02Page 31

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

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

1.03Page 31

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

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

1.04Page 31

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

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

1.05Page 31

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

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

1.06Page 31

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

\[\frac{(1 + i)(1 + \sqrt{3}i)}{1 - i}\] .

1.07Page 31

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

\[\frac{2 + 3i}{4 + 5i}\]

1.08Page 31

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

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

1.09Page 31

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

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

1.1Page 31

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

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

1.11Page 31

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

\[\left( \frac{1}{1 - 4i} - \frac{2}{1 + i} \right)\left( \frac{3 - 4i}{5 + i} \right)\]

1.12Page 31

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

\[\frac{5 + \sqrt{2}i}{1 - 2\sqrt{i}}\]

2.1Page 31

Find the real value of x and y, if

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

2.2Page 31

Find the real value of x and y, if

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

2.3Page 31

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`

2.4Page 31

Find the real value of x and y, if

\[(1 + i)(x + iy) = 2 - 5i\]

3.1Page 31

Find the conjugate of the following complex number:

4 − 5 i

3.2Page 31

Find the conjugate of the following complex number:

\[\frac{1}{3 + 5i}\]

3.3Page 31

Find the conjugate of the following complex number:

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

3.4Page 31

Find the conjugate of the following complex number:

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

3.5Page 31

Find the conjugate of the following complex number:

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

3.6Page 31

Find the conjugate of the following complex number:

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

4.1Page 32

Find the multiplicative inverse of the following complex number:

1 − i

4.2Page 32

Find the multiplicative inverse of the following complex number:

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

4.3Page 32

Find the multiplicative inverse of the complex number:

4 – 3i

4.4Page 32

Find the multiplicative inverse of the complex number.

`sqrt5 + 3i`

5Page 32

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

6.1Page 32

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

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

6.2Page 32

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

Im `(1/(z_1overlinez_1))`

7Page 32

Find the modulus of \[\frac{1 + i}{1 - i} - \frac{1 - i}{1 + i}\].

8Page 32

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

9Page 32

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

10Page 32

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

11Page 32

Find the smallest positive integer value of m for which \[\frac{(1 + i )^n}{(1 - i )^{n - 2}}\] is a real number.

 
12Page 32

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

13Page 32

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

14Page 32

If \[\left( \frac{1 - i}{1 + i} \right)^{100} = a + ib\] find (a, b).

15Page 32

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

16.1Page 32

Evaluate the following:

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

16.2Page 32

Evaluate the following:

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

16.3Page 32

Evaluate the following:

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

16.4Page 32

Evaluate the following:

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

16.5Page 32

Evaluate the following:

\[2 x^4 + 5 x^3 + 7 x^2 - x + 41, \text { when } x = - 2 - \sqrt{3}i\]

17Page 32

For a positive integer n, find the value of \[(1 - i )^n \left( 1 - \frac{1}{i} \right)^n\].

18Page 33

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

19Page 33

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

20Page 33

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

21Page 33

If z1 is a complex number other than −1 such that \[\left| z_1 \right| = 1\] and \[z_2 = \frac{z_1 - 1}{z_1 + 1}\] then show that the real parts of z2 is zero.

22Page 33

If \[\left| z + 1 \right| = z + 2\left( 1 + i \right)\],find z.

23Page 33

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

24Page 33

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

25Page 33

If z1z2z3 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 \[\left| z_1 + z_2 + z_3 \right|\] .

26Page 33

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

Exercise 13.3 [Page 39]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.3 [Page 39]

1.1Page 39

Find the square root of the following complex number:

−5 + 12i

1.2Page 39

Find the square root of the following complex number:

−7 − 24i

1.3Page 39

Find the square root of the following complex number:

1 − i

1.4Page 39

Find the square root of the following complex number:

 −8 − 6i

1.5Page 39

Find the square root of the following complex number:

8 −15i

1.6Page 39

Find the square root of the following complex number:

\[- 11 - 60\sqrt{- 1}\]

1.7Page 39

Find the square root of the following complex number:

 \[1 + 4\sqrt{- 3}\]

1.8Page 39

Find the square root of the following complex number:

 4i

1.9Page 39

Find the square root of the following complex number:

i

Exercise 13.4 [Pages 57 - 58]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.4 [Pages 57 - 58]

1.1Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

1 + i

1.2Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

\[\sqrt{3} + i\]

1.3Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

1 − i

1.4Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

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

1.5Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

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

1.6Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

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

1.7Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

 sin 120° - i cos 120° 

1.8Page 57

Find the modulus and argument of the following complex number and hence express in the polar form:

 \[\frac{- 16}{1 + i\sqrt{3}}\]

2Page 57

Write (i25)3 in polar form.

3.1Page 57

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

3.2Page 57

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

 tan α − i

3.3Page 57

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

1 − sin α + i cos α

3.4Page 57

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

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

4Page 57

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

5Page 57

If z1z2 and z3z4 are two pairs of conjugate complex numbers, prove that \[\arg\left( \frac{z_1}{z_4} \right) + \arg\left( \frac{z_2}{z_3} \right) = 0\].

6Page 58

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

Exercise 13.5 [Pages 62 - 63]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.5 [Pages 62 - 63]

1Page 62

Write the values of the square root of i.

2Page 62

Write the values of the square root of −i.

3Page 62

If x + iy =\[\sqrt{\frac{a + ib}{c + id}}\] then write the value of (x2 + y2)2.

4Page 62

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

5Page 62

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

6Page 62

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

7Page 62

Write 1 − i in polar form.

8Page 62

Write −1 + \[\sqrt{3}\] in polar form .

9Page 62

Write the argument of −i.

10Page 62

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

11Page 62

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

12Page 62

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

13Page 62

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

14Page 63

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

15Page 63

Write the value of \[\sqrt{- 25} \times \sqrt{- 9}\].

16Page 63

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

17Page 63

Write the value of \[\arg\left( z \right) + \arg\left( \bar{z} \right)\].

18Page 63

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

19Page 63

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

20Page 63

Write the conjugate of \[\frac{2 - i}{\left( 1 - 2i \right)^2}\] .

21Page 63

If n ∈ \[\mathbb{N}\] then find the value of \[i^n + i^{n + 1} + i^{n + 2} + i^{n + 3}\] .

22Page 63

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

23Page 63

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

24Page 63

Write the argument of \[\left( 1 + i\sqrt{3} \right)\left( 1 + i \right)\left( \cos\theta + i\sin\theta \right)\].

Disclaimer: There is a misprinting in the question. It should be  \[\left( 1 + i\sqrt{3} \right)\]  instead of \[\left( 1 + \sqrt{3} \right)\].

Exercise 13.6 [Pages 63 - 66]

RD Sharma solutions for Mathematics [English] Class 11 13 Complex Numbers Exercise 13.6 [Pages 63 - 66]

1Page 63

The value of \[(1 + i)(1 + i^2 )(1 + i^3 )(1 + i^4 )\] is.

  • 2

  • 0

  • 1

  • i

2Page 63

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

  • π

  • `pi/2`

  • `pi/3`

  • `pi/6`

3Page 63

If (1+i)(1 + 2i)(1+3i)..... (1+ ni) = a+ib,then 2 ×5 ×10 ×...... ×(1+n2) is equal to.

  • `sqrt(a^2 +b^2)`

  • `sqrt(a^2 +b^2)`

  • `sqrt(a^2 - b^2)`

  • `a^2 +b^2`

  • `a^2 -b^2`

  • a+b

4Page 63

If\[\sqrt{a + ib} = x + iy,\] then possible value of \[\sqrt{a - ib}\] is

  • \[x^2 + y^2\]

  • \[\sqrt{x^2 + y^2}\]

  • x + iy

  • x − iy

  • \[\sqrt{x^2 - y^2}\]

5Page 64

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

  • \[\left| z \right| = 1, \text { arg }(z) = \frac{\pi}{4}\]

  • \[\left| z \right| = 1, \text { arg }(z) = \frac{\pi}{6}\]

  • \[\left| z \right| = \frac{\sqrt{3}}{2},\text {  arg }(z) = \frac{5\pi}{24}\]

  • \[\left| z \right| = \frac{\sqrt{3}}{2}, \text { arg }(z) = \tan^{- 1} \frac{1}{\sqrt{2}}\]

6Page 64

The polar form of (i25)3 is

  • \[\cos\frac{\pi}{2} + i \sin\frac{\pi}{2}\]

  • cos π + i sin π

  •  cos π − i sin π

  • \[\cos\frac{\pi}{2} - i \sin\frac{\pi}{2}\]

7Page 64

If i2 = −1, then the sum i + i2 + i3 +... upto 1000 terms is equal to

  • 1

  • −1

  • i

  • 0

8Page 64

If \[z = \frac{- 2}{1 + i\sqrt{3}}\],then the value of arg (z) is

  • π

  • \[\frac{\pi}{3}\]

  • \[\frac{2\pi}{3}\]

  • \[\frac{\pi}{4}\]

9Page 64

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

  • \[\cot\frac{\theta}{2}\]

  • cot θ

  • \[i \cot\frac{\theta}{2}\]

  • \[i \tan\frac{\theta}{2}\]

10Page 64

If (1 + i) (1 + 2i) (1 + 3i) .... (1 + ni) = a + ib, then 2.5.10.17.......(1+n2)=

  • a − ib

  • a2 − b2

  • a2 + b2

  • none of these

11Page 64

If \[\frac{( a^2 + 1 )^2}{2a - i} = x + iy, \text { then } x^2 + y^2\] is equal to

  • \[\frac{( a^2 + 1 )^4}{4 a^2 + 1}\]

  • \[\frac{(a + 1 )^2}{4 a^2 + 1}\]

  • \[\frac{( a^2 - 1 )^2}{(4 a^2 - 1 )^2}\]

  • none of these

12Page 64

The principal value of the amplitude of (1 + i) is

  • \[\frac{\pi}{4}\]

  • \[\frac{\pi}{12}\]

  • \[\frac{3\pi}{4}\]

  • π

13Page 64

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

 
  •  16

  • 8

  • 4

  • 2

14Page 64

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

  • `|overlinez/z|`

  • \[\left| z \right|\]

  • `|overlinez|`

  • none of these

15Page 64

If a = 1 + i, then a2 equals

  • 1 − i

  •  2i

  •  (1 + i) (1 − i)

  • i − 1.

16Page 64

If (x + iy)1/3 = a + ib, then \[\frac{x}{a} + \frac{y}{b} =\]

  • 0

  • 1

  • −1

  • none of these

17Page 64

\[(\sqrt{- 2})(\sqrt{- 3})\] is equal to

  • \[\sqrt{6}\]

  • \[- \sqrt{6}\]

  • \[i\sqrt{6}\]

  • none of these.

18Page 65

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

  •  60°

  • 120°

  • 210°

  • 240°

19Page 65

If \[z = \left( \frac{1 + i}{1 - i} \right)\] then z4 equals

  •  1

  • −1

  • 0

  • none of these

20Page 65

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

  • 0

  • \[\frac{\pi}{2}\]

  • π

  • none of these.

21Page 65

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

  • \[\frac{1}{13}\]

  • \[\frac{1}{5}\]

  • \[\frac{1}{12}\]

  • none of these

22Page 65

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

  • 1

  • \[1/\sqrt{26}\]

  • \[5/\sqrt{26}\]

  • none of these

23Page 65

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

  • \[2 \sin\frac{\theta}{2}\]

  • \[2 \cos\frac{\theta}{2}\]

  • \[2\left| \sin\frac{\theta}{2} \right|\]

  • \[2\left| \cos\frac{\theta}{2} \right|\]

24Page 65

If \[x + iy = (1 + i)(1 + 2i)(1 + 3i)\],then x2 + y2 =

  • 0

  • 1

  • 100

  • none of these

25Page 65

If \[z = \frac{1}{1 - cos\theta - i sin\theta}\] then Re (z) =

  • 0

  • \[\frac{1}{2}\]

  • \[\cot\frac{\theta}{2}\]

  • \[\frac{1}{2}\cot\frac{\theta}{2}\]

26Page 65

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

  • 9/85

  •  −9/85

  •  53/85

  • none of these

27Page 65

If \[\frac{1 - ix}{1 + ix} = a + ib\] then \[a^2 + b^2\]

  • 1

  • -1

  • 0

  • none of these

28Page 65

If θ is the amplitude of \[\frac{a + ib}{a - ib}\] , than tan θ =

  • \[\frac{2a}{a^2 + b^2}\]

  • \[\frac{2ab}{a^2 - b^2}\]

  • \[\frac{a^2 - b^2}{a^2 + b^2}\]

  • none of these

29Page 65

If \[z = \frac{1 + 7i}{(2 - i )^2}\] , then

  • \[\left| z \right| = 2\]

  • \[\left| z \right| = \frac{1}{2}\]

  • amp (z) = \[\frac{\pi}{4}\]

  •  amp (z) = \[\frac{3\pi}{4}\]

30Page 65

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

  • 0

  • \[\frac{\pi}{2}\]

  • \[- \frac{\pi}{2}\]

  •  π

31Page 66

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

  • \[- \frac{\pi}{2}\]

  • \[\frac{\pi}{2}\]

  • \[\frac{3\pi}{2}\]

  • \[\frac{5\pi}{2}\]

32Page 66

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

  • \[\frac{\pi}{3}\]

  • \[- \frac{\pi}{3}\]

  • \[\frac{\pi}{6}\]

  • \[- \frac{\pi}{6}\]

33Page 66

The value of (i5 + i6 + i7 + i8 + i9) / (1 + i) is

  • \[\frac{1}{2}(1 + i)\]

  • \[\frac{1}{2}(1 - i)\]

  • 1

  • \[\frac{1}{2}\]

34Page 66

\[\frac{1 + 2i + 3 i^2}{1 - 2i + 3 i^2}\] equals

  • i

  • -1

  • \[-\]i

  • 4

35Page 66

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 

  • -1

  • -2

  • -3

  • -4

36Page 66

The value of \[(1 + i )^4 + (1 - i )^4\] is

  • 8

  • 4

  • -8

  • -4

37Page 66

If \[z = a + ib\]  lies in third quadrant, then \[\frac{\bar{z}}{z}\] also lies in third quadrant if

  • \[a > b > 0\]

  • \[a < b < 0\]

  • \[b < a < 0\]

  • \[b > a > 0\]

38Page 66

If \[f\left( z \right) = \frac{7 - z}{1 - z^2}\] , where \[z = 1 + 2i\] then \[\left| f\left( z \right) \right|\] is

  • \[\frac{\left| z \right|}{2}\] 

  • \[\left| z \right|\]

  • \[2\left| z \right|\]

  • none of these

39Page 66

A real value of x satisfies the equation  \[\frac{3 - 4ix}{3 + 4ix} = a - ib (a, b \in \mathbb{R}), if a^2 + b^2 =\]

  • 1

  • -1

  • 2

  • -2

40Page 66

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

  • circle x2 + y2 = 1

  • the x−axis

  • the y−axis

  • the line x + y = 1

41Page 66

If z is a complex numberthen

  • \[\left| z \right|^2 > \left| z \right|^2\]

  • \[\left| z \right|^2 = \left| z \right|^2\]

  • \[\left| z \right|^2 < \left| z \right|^2\]

  • \[\left| z \right|^2 \geq \left| z \right|^2\]

42Page 66

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

 

  • \[\left| z_1 z_2 \right| = \left| z_1 \right|\left| z_2 \right|\]

  • \[\arg\left( z_1 z_2 \right) = \arg\left( z_1 \right) \arg\left( z_2 \right)\]

  • \[\left| z_1 + z_2 \right| = \left| z_1 \right| + \left| z_2 \right|\]

  • \[\left| z_1 + z_2 \right| \geq \left| z_1 \right| + \left| z_2 \right|\]

43Page 66

If the complex number \[z = x + iy\] satisfies the condition \[\left| z + 1 \right| = 1\], then z lies on

  • x−axis

  • circle with centre (−1, 0) and radius 1

  • y−axis

  • none of these

Solutions for 13: Complex Numbers

Exercise 13.1Exercise 13.2Exercise 13.3Exercise 13.4Exercise 13.5Exercise 13.6
RD Sharma solutions for Mathematics [English] Class 11 chapter 13 - Complex Numbers - Shaalaa.com

RD Sharma solutions for Mathematics [English] Class 11 chapter 13 - Complex Numbers

Shaalaa.com has the CBSE, Karnataka Board PUC Mathematics Mathematics [English] Class 11 CBSE, Karnataka Board PUC solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. RD Sharma solutions for Mathematics Mathematics [English] Class 11 CBSE, Karnataka Board PUC 13 (Complex Numbers) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. RD Sharma textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Mathematics [English] Class 11 chapter 13 Complex Numbers are Argand Plane and Polar Representation, Algebra of Complex Numbers - Equality, Algebraic Properties of Complex Numbers, Need for Complex Numbers, Square Root of a Complex Number, Conjugate of a Complex Number, Algebraic Operations of Complex Numbers, Concept of Complex Numbers.

Using RD Sharma Mathematics [English] Class 11 solutions Complex Numbers exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in RD Sharma Solutions are essential questions that can be asked in the final exam. Maximum CBSE, Karnataka Board PUC Mathematics [English] Class 11 students prefer RD Sharma Textbook Solutions to score more in exams.

Get the free view of Chapter 13, Complex Numbers Mathematics [English] Class 11 additional questions for Mathematics Mathematics [English] Class 11 CBSE, Karnataka Board PUC, and you can use Shaalaa.com to keep it handy for your exam preparation.

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