evaluate the derivative f(x) if f(x) = pi(x) + 1/cos^2(pi(x)), x=1/4

Question

in case its 1 over cos²(pi(x))

Answer 1

f(x) = pi(x) + 1/cos^2(pi(x)), x=1/4

f(x) = πx + 1/Cos²(πx) at x=1/4

f'(x) = π + d/dx [sec^2(πx)] =π+ π[sec(πx)Tan(πx)

= π+ 2πSec²(πx)Tan(πx)

= π + .086150

= 3.2277