# Thread: Finding the derivatives of Eqations containing trig

1. ## Finding the derivatives of Eqations containing trig

Hey Guys Im really lost here.

dy/dx, if y = xln[tan(2x)]

dy/dx, if x^2(y) + sin(x + y) = x

First off dy/dx is just the same as finding the derivative correct? How do I find these?

Is there a good website you could recomend with sample questions and detailed solutions? Thanks

2. Originally Posted by enjoiii
Hey Guys Im really lost here.

dy/dx, if y = xln[tan(2x)]

dy/dx, if x^2(y) + sin(x + y) = x

First off dy/dx is just the same as finding the derivative correct? How do I find these?

Is there a good website you could recomend with sample questions and detailed solutions? Thanks
You need to review implicit differentiation and the chain rule for these types of problems.

The first one:

$\displaystyle dy/dx = x' ln[tan(2x)] + x (ln[tan(2x)])'$ <-- Product Rule on the right side

$\displaystyle dy/dx = ln[tan(2x)] + x \frac{1}{tan(2x)} sec^2(2x) * 2$ <--- Chain Rule applied twice.

See if you can try the second one on your own!

Good luck!