Trigonometric functions

Answer:
C
Step-by-step explanation:
To find the x- intercept let y = 0, hence
cos([tex]\frac{x}{2}[/tex]) = 0
[tex]\frac{x}{2}[/tex] = [tex]cos^{-1}[/tex](0 ) = [tex]\frac{\pi }{2}[/tex]
multiply both sides by 2
x = π ← x- intercept