**NCERT
Solutions for Class 11 Maths Chapter 5 Complex Numbers and Quadratic Equations
Ex 5.1**

NCERT Solutions for Class 11 Maths Chapter 5 Complex Numbers and
Quadratic Equations Ex 5.1 are the part of NCERT Solutions for Class 11 Maths.
Here you can find the NCERT Solutions for Class 11 Maths chapter 5 Complex
Numbers and Quadratic Equations Ex 5.1.

**Express
each of the complex number given in the Exercises 1 to 10 in the form a + ib.
**

**Ex 5.1
Class 11 Maths Question 1.**

(5i)(−3i/5)

**Solution.**

(5i)(−i3/5)

= -3i^{2} = -3(-1)
[∵ i^{2} = -1]

= 3 = 3 + 0i

**Ex 5.1 Class 11
Maths Question 2.**

i^{9 }+ i

^{19}

**Solution.**

i^{9 }+ i^{19 }=
(i^{2})^{4}.i + (i^{2})^{9}.i = (-1)^{4}.i
+ (-1)^{9}.i

= i + (-1)i = i – i = 0 = 0 +
0i

**Ex 5.1 Class 11
Maths Question 3.**

i^{-39}

**Solution.**

**Ex 5.1 Class 11
Maths Question 4.**

3(7 + i7) + i(7 + i7)

**Solution.**

3(7 + i7) + i(7 + i7) = 21 + 21i + 7i + 7i^{2}

= 21 + (21 + 7)i + (-1)7 = 21 – 7 + 28i

= 14 + 28i

**Ex 5.1 Class 11
Maths Question 5.**

(1 – i) – (-1 + i6)

**Solution.**

(1 – i) – (-1 + i6) = 1 – i + 1 – 6i

= (1 + 1) – i(1 + 6)

= 2 – 7i

**Ex 5.1 Class 11 Maths Question 6.**

**Solution.**

**Ex 5.1 Class 11 Maths Question 7.**

**Solution.**

**Ex 5.1 Class 11
Maths Question 8.**

(1 – i)^{4}

**Solution.**

(1 – i)^{4} = [(1 – i)^{2}]^{2} = [1 – 2i + i^{2}]^{2}

= [1 – 2i + (-1)]^{2}

= (-2i)^{2} = 4i^{2} = 4(-1) = –4

= –4 + 0i

**Ex 5.1 Class 11 Maths Question 9.**

(1/3 + 3i)^{3}

**Solution.**

**Ex 5.1 Class 11 Maths Question 10.**

(−2 – 1/3 i)^{3}

**Solution.**

**Find the multiplicative
inverse of each of the complex numbers given in the Exercises 11 to 13.**

**Ex 5.1 Class 11
Maths Question 11.**

4 – 3i

**Solution.**

**Ex 5.1 Class 11 Maths Question 12.**

√5 + 3i

**Solution.**

**Ex 5.1 Class 11
Maths Question 13.**

-i

**Solution.**

**Ex 5.1 Class 11 Maths Question 14.**

Express the following expression in the form of a + ib:

**Solution.**

We have,