They want you calculate the derivative and evaluate it at the point, where y= -1. The derivative is= 2x - 2. (1) The point where y= -1 is -1 = x^2 - 2x x^2 - 2x + 1 = 0 (x-1)^2 = 0 x = 1. So, we substitute x= 1 into the expression for the derivative (1), and we get the gradient gradient = 2*1 - 2 = 0. ANSWER ANSWER. The gradient is zero at the point where y = -1.