# Rates of change

• October 25th 2009, 11:31 AM
live_laugh_luv27
Rates of change
Let $g(x) = x^2-3x+4$

a. Find the average rate of change of $g$ over the interval $[1,4]$

b. Find the rate of change of $g$ at $x=3$

c. Find the equation of the tangent line at $x=3$

d. Find the equation of the normal line at $x=3$

Here are my answers, are they correct?

a. 2

b. 3

c. $y-4=3(x-3)$

d. $y-4=-\frac{1}{3}(x-3)$
• October 25th 2009, 11:41 AM
Arturo_026
As far as i can see it looks good.
So for a you used f(b)-f(a)/b-a , for b you found f'(3) and your line equations look good.
Nice job.
• October 25th 2009, 11:44 AM
live_laugh_luv27
Quote:

Originally Posted by Arturo_026
As far as i can see it looks good.
So for a you used f(b)-f(a)/b-a , for b you found f'(3) and your line equations look good.
Nice job.

ok, thanks..just wanted to make sure I'm doing the problem right.