Question

Given f(x)=x^3-4x^2+x-2. State the interval(s) on which f is increasing and on which f is decreasing.

Answer 1

Find derivative, set to 0, solve for x. Intervals positive increasing, negative decreasing.

Answer 2

I don't know how to do derivatives, I'm only in pre-calc.

Answer 3

Two ways, you can do either one or do both, using one as a check.
Analyse graph. Increasing when graph is going 'up' from left to right.
2nd method: solve for x. Investigate from negative infinity, over intervals of x, to positive infinity. Input x values, if y (also known as f(x), is getting bigger over interval increasing; if x values produce smaller y values decreasing.