Question

Consider the function y = 3x5 – 25x3 + 60x + 1. Use the first derivative test to decide whether this function has a maximum at x = 1

Answer 1

dy/dx = 15x^4 -75x^2 + 60
d^2y/dx = 60x^3 - 150x
when x = 1 60 -150 = negative

Answer 2

So is the derivative negative to the left of x = 1 and positive to the right of x = 1?

Answer 3

Help?