Which formula gives the x-coordinates of the maximum values for y = cos(x)? k pi for any integer k k pi for k = 0, plus-or-minus 2, plus-or-minus 4, ellipsis StartFraction k pi Over 2 EndFraction for any positive integer k StartFraction k pi Over 2 EndFraction for k = 0, plus-or-minus 2, plus-or-minus 4, ellipsis