The function is given as ,
[tex]f(x)=\cos x.[/tex]
According to the trigonomteric values of cos ,
[tex]\cos \text{ 0}=1[/tex][tex]\cos \text{ }\frac{\Pi}{2}=0[/tex][tex]\cos \Pi=-1[/tex][tex]\cos \frac{3\Pi}{2}=0[/tex]
The graph suitable for the cos x is, the option c which satisfy the above conditions.
Hence the correct grapha and option is c.
