# Equation of Tangent Line

1. Mar 16, 2009

### husky88

1. The problem statement, all variables and given/known data

Find the equation of the tangent line on the function, f(x) = X$$^{2}$$-4x+1, which is perpendicular to the line, x+2y=10.

2. Relevant equations

3. The attempt at a solution

x+2y=10
2y = 10-x
y=-1/2x+5
Slope of perpendicular is -1/2, so slope of tangent is 2.
The derivative of f(x):
f'(x)= 2x-4.
f'(x) represents the slope of the tangent = 2
Where can I go from here?
Thank you.

2. Mar 16, 2009

### husky88

I figured out my answer. :)
I don't need a reply, but I don't know how to delete the thread.