Question

what basic trigonometric identity would you use to verify that sin^2 x + cos^2 x/ cos x = sec x?
a. sin x = 1/csc x
b. 1 + cot^2 x = csc^2 x
c. cos^2 x + sin^2 x = 1
d. cos x = 1/sec x

Answer 1

Third one