Question

If $f\left(x\right)=\cos \left[\frac{{\pi }^2}{2}\right]x+\cos [-\frac{{\pi }^2}{2}]x$, where $[.]$ denotes the greatest integer function, then which of the following is not correct

• A. $f\left(0\right)=1$
• B. $f\left(\frac{\pi }{3}\right)=\frac{1}{\sqrt{3}+1}$
• C. $f\left(\frac{\pi }{2}\right)=0$
• D. $f\left(\pi \right)=1$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $f\left(0\right)=1$
B $f\left(\frac{\pi }{3}\right)=\frac{1}{\sqrt{3}+1}$
D $f\left(\pi \right)=1$