Originally Posted by

**sk8erboyla2004** I want to be sure I did this right

I had to find the equation of the tangent line I was given

$\displaystyle f(x)=10-cos(3x)$ at $\displaystyle x=\pi$

So I take the derivative with respect to x with meaning all I had to really do is take the derivative of the function so that gives me

$\displaystyle \frac{dy}{dx}=3sin(3x)$

which this gives me my slope when i plug in x

which gives me 0

and to find the y of the coords. I plug in x in the originial function and get 11

and when i do point slope form i get

y = 11 which cant be correct or is it?