# Tangent lines

1. May 9, 2007

### Weave

1. The problem statement, all variables and given/known data
Given: $$f(x)=x^2-4x+5$$ find equation for two lines that are tangent to the graph and pass through the point P(0,1)

2. Relevant equations
$$f(x)=x^2-4x+5$$
$$\frac{dy}{dx}=2x-4$$
Equation of the tangent line/s
$$f(x)=f'(a)(x-a)+f(a)$$

3. The attempt at a solution
Just need to get started

2. May 9, 2007

### chroot

Staff Emeritus
You seem to have everything you need. You have the derivative, which gives you the slope of the tangent line at any point you plug in. You're supposed to find the tangent line at the point (0, 1), which means you need the slope at x=0. You can use point-slope form to find the line equation if you want, or you can literally just plug the numbers into the general line equation you were given.

- Warren

3. May 9, 2007

### Weave

lol... revelation I got it.
Don't you love it when you make things more complicated then they need to be?:rofl: