Question

help please:
Find the interval on which the f(x) = -2x^3-9x^2-12x+1 is increasing or decreasing

Answer 1

f'(x) determines de/in crease.
f''(x) determines concavity.

so you need to find the first derivative and set it equal to zero.
When the derivative is greater than 0, f(x) is increasing.
When the derivative is less than 0, f(x) is decreasing.

Answer 2

differentiate (i.e. take the derivative) each term.

Answer 3

yep
\[f'(x)= -6x^2-18x-12\]

Answer 4

yes, that is correct.

Answer 5

wait