Intervals of a derivative
I'm trying to find the intervals of the derivative of a function that I found on my book but I'm having some troubles understanding it, so I thought of trying to find some help here.
The function is .
So I need to find the derivative of this function, study it and find the intervals (where it's increasing and where it's decreasing)
This is the solution: and .
So the function is decreasing in and while increasing in and .
Here is where I am having some troubles:
- How do I find those intervals? I know that I need to solve the equations, but I 'm stuck there
- How can I find where the function is decreasing and increasing?