x(t) = -0.01t^3 + t^2 - 20t + 4
Min is when t = 12.3
Max is when t = 54.4
The Attempt at a Solution
I got -0.03t^2 + 2t - 20 as the derivative.
I substituted in t = 12.3 and 54.4 and got 0.02 and 0.19 which don't seem right at all.
Because: when t is 12.3, the position(x) is -100. When t is 54.4 the position(x) is 250.