find dy/dx of
y= (cosx/x) + (x/cosx)
i got up to
((xsinx-cosx)/x^2 ) + ((cosx+sinx)/cosx^2))
and i don't know how to simplify it.
after trying your way and my way, i found that the problem is generally easier to do your way. however, i do not see a worth-while way to simplify anything, so just leave the answer as:
$\displaystyle y' = \frac {-x \sin x - \cos x}{x^2} + \frac {\cos x + \sin x}{\cos^2 x}$
or if you feel like, you can combine these fractions to get: $\displaystyle \frac {-x \sin x \cos^2 x - \cos^3 x + x^2 \cos x + x^2 \sin x}{x^2 \cos^2 x}$
but i don't see any motivation for doing even that