# Math Help - Differentiate a function.

1. ## Differentiate a function.

Find dy/dx:

y= xtan(u^2)/ln(x)

This is just some Diff eqn review for my fluid mechanic class, and Im a bit rusty any help would be appreciated!

I tried integrating both sides but I got lost when I tried to integrate for x...

2. You don't integrate to find a derivative...

Also, what is $\displaystyle u$? Is it a function of $\displaystyle x$ or a constant?

3. u = 1+ x^3

4. Why didn't I know that? My psychic powers are a little off this morning...

Anyway $\displaystyle y = \frac{x\tan{\left[(1+x^3)^2\right]}}{\ln{x}}$.

You need to use the Quotient Rule, then the Product Rule, then the Chain Rule... See how you go.

5. y = tan(1+x^3)^2 (ln(x))*tan(1+x^3)^2 + 6x^3 sec^2 (x^3+1)tan(x^3+1) / ln(x)^2

I think thats about right just wasn't expecting that for a damn fluids class lol Thanks.