Question

Find the critical points and the interval on which the given function is increasing or decreasing, and apply the First Derivative Test to each critical point
f(x)= (7/4)x^4+(28/3)x^3+(-63/2)x^2-252x
critical points in increasing order:
c1=? min or max?
c2=? min or max?
c3=? min or max?

Answer 1

y' = 7x^3+28x^2-63x-252
= 7(x+4)(x+3)(x-3)

Now things should be easy.
You know y is increasing when y' > 0...