Question

Me ajudem nessa...

$\int\limits{ \frac{senx}{cos^{2}x}} \, dx$

Answer 1

$\int \frac{sen(x)}{cos^2(x)} dx$

substituição
u = cos(x)
du = -sen(x) dx

$\int \left(\frac{-1}{u^2}\right) du=\int \left(-u^{-2}\right) du=- \frac{u^{-1}}{-1}+C\\\\ = \frac{1}{u}+C\\\\= \frac{1}{cos(x)}+C \\\\= sec(x)+ C$