hello i need help for derivative: ( sin x ) / ( cos x )

Question

thanks for your help

Answer 1

Hints:
Use the quotient rule:
d(u/v)=(vdu-udv)/v^2
set
u=sin(x) du/dx=cos(x)
v=cos(x) dv/dx=-sin(x)
and
finally use the identity
sec(x)=1/cos(x)