# NCERT Solutions For Class 10 Maths Chapter 8 Introduction to Trigonometry Ex 8.4

### Ex 8.4 Class 10 Maths Question 1.

Express the trigonometric ratios sin A, sec A and tan A in terms of cot A.Solution:

Solution for Ex 8.4 Class 10 Maths Question 1 ### Ex 8.4 Class 10 Maths Question 2.

Write all the other trigonometric ratios of ∠A in terms of sec A.

#### Solution for Ex 8.4 Class 10 Maths Question 2 ### Ex 8.4 Class 10 Maths Question 3.

Evaluate: #### Solution for Ex 8.4 Class 10 Maths Question 3 Ex 8.4 Class 10 Maths Question 4.
Choose the correct option. Justify your choice.
(i) 9 sec² A – 9 tan² A = ……
(A) 1
(B) 9
(C) 8
(D) 0

(ii) (1 + tan θ + sec θ) (1 + cot θ – cosec θ) = ………..
(A) 0
(B) 1
(C) 2
(D) -1

(iii) (sec A + tan A) (1 – sin A) = ………….
(A) sec A
(B) sin A
(C) cosec A
(D) cos A

(iv) (A) sec² A
(B) -1
(C) cot² A
(D) tan² A

#### Solution for Ex 8.4 Class 10 Maths Question 4 ### Ex 8.4 Class 10 Maths Question 5.

Prove the following identities, where the angles involved are acute angles for which the expressions are defined. #### Solution for Ex 8.4 Class 10 Maths Question 5  