Q10 of 268 Page 5

Prove the followings identities:
(1 – sin θ)(1 + sin θ) = cso² θ

Taking LHS = (1 – sinθ)(1+ sinθ)

Using identity , (a + b) (a – b) = (a² – b²) , we get

= (1)² – (sinθ)²

= 1 – sin² θ

= cos² θ [∵ cos² θ + sin² θ = 1]

= RHS

Hence Proved

If, sin 50° = α then write the value of cos 50° in terms of α.

If x cos A = 1 and tan A = y, then what is the value of x² – y².

Prove the followings identities:

(1 + cos θ)(1 – cos θ) = sin²θ

Prove the followings identities:

Prove the followings identities:(1 – sin θ)(1 + sin θ) = cso2 θ