Posted by Tom on Monday, March 5, 2012 at 4:39pm.
hello i need help for derivative: ( sin x ) / ( cos x )
thanks for your help

Math  MathMate, Monday, March 5, 2012 at 5:12pm
Hints:
Use the quotient rule:
d(u/v)=(vduudv)/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)