Posted by
**Jonah** on
.

Find the derivative of the function.

y= xcosx - sinx

What's the derivative?

I get only one trig function. I will be happy to critique your work or thinking. Use the chain rule on the first term.

Our class hasn't covered Chain Rule. Only product and quotient rule. Apparently the work should go...

y= -xsinx + cosx - cosx

I get where the -xsinx and -cosx came from. But the +cosx?

Nevermind. I figured it out. Used the product rule on the xcosx, then found the derivative of the -sinx.