9. Consider the function f(x)=x^4-50x^2+9, -4≤x≤11

Question

This function has an absolute value equal to _____ and an absolute maximum value equal to _____

Answer 1

Hi Katie,

The derivative f'(x) = 4x^3 - 100x = 4x (x^2 - 25) = 4x (x - 5)(x + 5) has two zeroes between -4 and 11. Both the endpoints -4 and 11 as well as the two zeroes are good candidates to be absolute min and max, so use the function f to determine the values at those points.