Posted by **Anonymous** on Saturday, March 3, 2007 at 12:52am.

We are calculating the slope of the function f(x) = sqrt(x) at x = 4.

f(4) = 2

f(4+h) = sqrt(4 + h)

[f(4+h) - f(4)]/h =?

You have to pick a small h,and calculate it. Then pick an even smaller value and calculate it again. That's called taking the limit as h-> 0

If you pick h=0.1, you get a slope of

0.2484

If you pick h=0.01, you get a slope of 0.2498

Try an even lower value of h and you will see the trend to the limit.

The exact value of the slope, using the formula for the derivative at x=4, is (1/2)/(sqrt 4) = 1/4