Mathematics - Inverse Trigonometric Functions Question with Solution | TestHub

A continuous even periodic function $f$ with period 8 is such that $f(0)=0,f(1)=-2,f(2)=1,f(3)=2,f(4)=3$. Then the value of NEGATIVE of ${\tan }^{-1}\left(\tan \left(f(-5)+f(20)+{\cos }^{-1}(f(-10)+f(17))\right)\right)$ is equal to

(Take $\pi =3.14$)