# Thread: Maxima and minima trig problem

1. ## Maxima and minima trig problem

I am having a problem trying to figure out the maxima and minima points of the function:
$\displaystyle y=cosx(1+sinx), [0, 2\pi]$
I got to the derivative:
$\displaystyle 2sin^2x+sinx=-1$
But I don't know what to do from there. Any help would be appreciated.

2. ## It's a quadratic

Your final equation is a quadratic - use the quadratic equation to find the roots.

By the way, check your derivative. I seem to be getting a +1.