# Differentiate with respect the right variable

• May 11th 2010, 06:59 AM
coolhacker
Differentiate with respect the right variable
Hi

i really need help with these questions:

1. y=sin t cos t

2. y= e^x/sin2x

plz help me solve these problems

thxx
• May 11th 2010, 07:07 AM
1) $\frac{dy}{dt} = (sin(t))'cos(t) + sin(t)(cos(t))' = (cos(t))^2-(sin(t))^2$
2) $\frac{dy}{dx} = \frac{(e^x)'sin(2x)-e^x(sin(2x))'}{(sin(2x))^2} = \frac{e^x sin(2x)-2e^x cos(2x)}{(sin(2x))^2}$