# Tangent lines and derivatives Help!

• October 19th 2008, 03:26 PM
Casas4
Tangent lines and derivatives Help!
I can solve derivatives alright but I don't understand tangent lines at all.
Find the equation of the tangent line to the curve http://webwork.math.uwyo.edu/webwork...494d69bcd1.png at the point http://webwork.math.uwyo.edu/webwork...61ec146821.png. The equation of this tangent line can be written in the form http://webwork.math.uwyo.edu/webwork...9a0aa8b841.png
where m is?
And b is?
I solved the derivative down to
6[2sin(x)+sec(x)tan(x)]
I think this is right and hopefully you needed to solve the derivative.
Thanks to anyone who can help
Casas4
• October 19th 2008, 03:50 PM
Plato
If $f$ is differentiable at $x_0$ then the equation of the tangent line at $
\left( {x_0 ,f\left( {x_0 } \right)} \right)$
is $y = f'\left( {x_0 } \right)\left( {x - x_0 } \right) + f\left( {x_0 } \right)$.
Note that $f'\left( {x_0 } \right)$ is the slope of the tangent line.
• October 19th 2008, 04:01 PM
Casas4
still confused
do i plug in (pi/3,6) with the equation y-y1=m(x-X1)? If so how do you turn the derivative in to an equation?
• October 19th 2008, 04:23 PM
Plato
Quote:

Originally Posted by Casas4
do i plug in (pi/3,6) with the equation y-y1=m(x-X1)? If so how do you turn the derivative in to an equation?

By asking that question, you have told me that you need some real help that is beyond an “On-Line” environment.
You need a sit-down with a live instructor.