Need help finding (a) Critical Numbers and (b) Inflection points for these two
1. $\displaystyle y = 2x - tanx $ ; $\displaystyle \frac{-pi}{2} < x < \frac{pi}{2}$
$\displaystyle y' = 2 - sec^2(x)$
$\displaystyle y'' = -sec(x)tan(x) $
2. $\displaystyle y = e^(-x) sinx $ ; 0 < or equal to x < or equal to 2pi
$\displaystyle y' = -e^x cosx $
$\displaystyle y'' = -e^x(-sinx) $ <--- Not sure if that's correct
I'm not very fond of trig functions and I need help with these two. I need help asap