Locate the local extrema of the function. (x) = x 2x + x - 7 O O O local max at x = local min at x = local max at x local min at x = 1 3 1. 3 1 3 local min at x = 1 local max at x = 1 1 3' local min at x = -1 local max at x = 1 O None of these choices