What is the derivative of y = (secx + tanx)(secx -tanx)y=(secx+tanx)(secxtanx)?

1 Answer
Dec 7, 2016

y' = 0

Explanation:

Start by rewriting in terms of sine and cosine. For this problem we use the identities sectheta = 1/costheta ad tantheta = sintheta/costheta.

y = (1/cosx + sinx/cosx)(1/cosx- sinx/cosx)

y = ((1 + sinx)/cosx)((1 - sinx)/cosx)

y = (1 - sin^2x)/cos^2x

y = cos^2x/cos^2x

y = 1

The derivative of any constant is 0.

y' = 0

Hopefully this helps!