If f(x) = sec x, tan x = 1, and x is in quadrant I, what is the value of the following.

Question

If f(x) = sec x, tan x = 1, and x is in quadrant I, what is the value of (f  f)(x)?

Grade 12 Advanced Functions

Please answer clearly and neatly. Thanks :)

Answer 1

Hi,

If x is limited to be in the first quadrant, that means 0 < x < π/2. We are also told that tan(x) = 1. The only value of x that fits both of these criteria is x = π/4

so (f * f)(x) = f²(x) = sec²(π/4) = 2