Question

If
$f\left(x\right)=\cos \left[{\pi }^2\right]x+\cos \left[-{\pi }^2\right]x$ , where $\left[x\right]$ stands for the greatest integer
function, then

• A. $f\left(\frac{\pi }{2}\right)=-1$
• B. $f\left(\pi \right)=1$
• C. $f\left(-\pi \right)=0$
• D. $f\left(\frac{\pi }{4}\right)=2$

Answer 1

Answer: (A), (C)

The correct options are
A $f\left(\frac{\pi }{2}\right)=-1$
C $f\left(-\pi \right)=0$