8. The function f(x)=2x^3+18x^2-162x+111, -9≤x≤4

Question

has two critical numbers A<B, with A=____ and B=_____

This function has an absolute minimum value equal to ______

and an absolute maximum value equal to ____

Answer 1

0 = y' = 6x^2 + 36x - 162

0 = 3x^2 + 18x - 81

0 = x^2 + 6x - 27

0 = ( x + 9)( x - 3 )

x=-9 or x=3

f(-9) = 2(-9)^3 + 18(-9)^2 - 162(-9) + 111

= 3 *" -729 + 18 * 81 + 162*9 + 111

= 840

(-9, 840)

(3, -159)