For the function y = cos(1/2 x) The x-intercept can be calculated by equating the function to zero and solving for x. So, y = cos(1/2 x) = 0 1/2 x = arc cos 0 1/2 x = 90° +180°n x =2 (90° +180°n) x = 180° + 360°n or converting to radians x = (180° + 360° n)(π/180°) x = π + 2π n where n is any whole number