Question

Verify the identity: (1-sinx)/cosx = cosx/(1+sinx)

Answer 1

Cross multiply the expression so that we can get

(1+sinx)(1-sinx) = cos^2 x

1 - sin^2 x = cos^2 x

cos^2 x + sin^2 x = 1

since

cos^2 x + sin^2 x = 1 

therefore 

1 = 1

the two expressions are identical in a trigonometric sense