Question

Verify the identity.
Please show your work.

Answer 1

Explanation:

To prove :

( 1 - sin x ) ( 1 + sin x ) = sec² x

LHS : -

( 1 - sin x ) ( 1 + sin x )

Formula / Identity : -

( a - b ) ( a + b ) = a² - b²

Here,

a = 1

b = sin x

( 1 - sin x ) ( 1 + sin x )

= 1 - sin² x

Identify : -

sin² θ + cos² θ = 1

cos² θ = 1 - sin² θ

Similarly,

1 - sin² x

= cos² x

= RHS

Hence verified.