Answer:
(5, -93) local minima, (-1, 15) local maxima
Step-by-step explanation:
differentiate this equation, we get
y' = 3x^2 - 12 x -15
the x-axis of the vertices are:
3x^2 - 12x - 15 = 0
(x-5)(3x+3) = 0
x1 = 5 and x2=-1
so the positions of the vertices are (5, -93) and (-1 , 15)
(5, -93) is the local minima, and (-1, 15) is the local maxima
