Evaluate the integral by given

Question

https://ibb.co/DpYzKXR

see the image

Answer 1

let u = f(x), du = f '(x) dx

when x=0 u = 1

when x =1 u= √3

∫du/(1+u²) = arctan(u) evaluated from √3 to 1

arctan(√3) - arctan(1) = π/3 - π/4 = π/12