ncert class 10 maths chapter 8 exercise 8.4
Answers
Answer:
Express the trigonometric ratios sin A, sec A and tan A in terms of cot A. Solution:
In photo
Ex 8.4 Class 10 Maths Question 2.
Write all the other trigonometric ratios of ∠A in terms of sec A. Solution:
In photo
Ex 8.4 Class 10 Maths Question 3.
Evaluate: Solution:
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) [latex s=2]\frac { 1+{ tan }^{ 2 }A }{ 1+cot^{ 2 }A }[/latex] = ………..
(A) sec² A. (B) -1. (C) cot² A. (D) tan² A
Solution:
In photo
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: in photo
Answer:
(cosec A -sinA ) (secA- cosA) =1/ tanA + cotA