Please advise

BL Consider the following function. y = x3 + 3x2 - 9x+ 9 Find y'(x). y' (x ) = 3x2+ 6x - 9 The graph of y(x) has a horizontal tangent line when y '(x) is equal to what value? y'(x) = 0 Set y'(x) equal to the value above and solve for x. (Enter your answers as a comma-separated list.) X = -3,1 Find the points on the given curve where the tangent is horizontal. smaller x-value (x, y) = 3.0 larger x-value ( x, y ) = 1,4