1. ## Finding Tangent Lines

f(x) = x^2 + x + 3

I know f ' (x) = 2x + 1.

Now how do I find the equation of the tangent line to the curve at x = -2, or any value of x for that matter

2. I suck at explaining this but this may help you to "see" what the tangent line is:
Tangent - Wikipedia, the free encyclopedia

3. equation of the tangenet line to the function f at x=a is :
y-f(a)=f`(a) (x-a)

4. Originally Posted by TWiX
equation of the tangenet line to the function f at x=a is :
$y-f(a)=f'(a) (x-a)$
this is correct

Hopefully you understand where this comes from, Zabulius. In particular, you should be aware that the derivative gives a formula for finding the slope at any value of x for a particular function. the tangent line is a straight line, and is hence of the form y = mx + b where m is the slope (hence given by the derivative) and b is the y-intercept. once you find the slope and a point the line passes through (this is the point (a, f(a)) in the above formula) you can find the equaiton of the line

5. Thanks to everyone for the help. I'm pretty sure I did a decent job on my exam this morning.