If the minimum value of the function f (x) = - 2x ^ 3-3x ^ 2 + 12x + 1 in the interval [M, 1] is - 17, then M =?

If the minimum value of the function f (x) = - 2x ^ 3-3x ^ 2 + 12x + 1 in the interval [M, 1] is - 17, then M =?

∵ f '(x) = - 6x & sup2; - 6x + 12, Let f' (x) = 0, then the stationary point x = - 2, x = 1
When x