some1 help me with this math problem i was sick,dont understand wat the professr is talking about !?

Question

determine the slope of the secant line for the curve defined by the equation
f(x)=1x^2+(-5)
for the points determined by x0=4 and x1=5
the slope of the secant line is m=____

Answer 1

it's is 9 but but it's hard to graph it in here sry at least you know the answer

Answer 2

A secant line of a curve is a line that intersects two or more points on the curve. The word secant comes from the Latin secare, for to cut.

First find the y coordinates of the two points:
f(x) = x^2 - 5
f(x0) = f(4) = 4^2 - 5 = 11
f(x1) = f(5) = 5^2 - 5 = 25 - 5 = 20
So the two points are:
(4, 11) and ( (5, 20)
Going from (4, 11) to (5, 20) you have gone up 9 units and over 1 unit, that's a slope of 9/1 = 9
Alternatively, you can use the formula for slope:
m = (y2 - y1)/(x2 - x1) = (20 - 11)/(5 - 4) = 9/1 = 9

Here's the pic:

http://s236.photobucket.com/albums/ff177/jsardi56/?action=view¤t=slopeofsecant10-19-07.jpg