I was asked to find the minimum and maximum values of the functions:
What I did so far:
$y' = 2\sin(2x)/(1+\cos^2x)^2$
How do I check if they are suspicious extrema points? After this function is cyclical and therefore only section that is not $(-\infty,\infty)$ can there be a local minimum/maximum.
$y' = \sin(2x)+4\cos^3(x)\cdot\sin(x)$