Posted by Casey on .
Estimate the instanteous rate of change f(x) = x/(x+5) at (-3, -3/2)
Could someone explain this question to me, this isn't exactly the same as polynomial functions >.<
It just says estimate so do that. add a small amount, say .1 to x and see how much f(x) changes
then the rate of change is (f(-3+.1) - f(3) )/.1
[f(-2.9) - f(3) ] / .1
= [-1.38 - (-1.5)]/.1
Now if you knew calculus you would have said:
dy/dx = [(x+5)(1) - x(1) ] / (x+5)^2
at x = -3 that is
5/4 = 1.25 well not bad
What did you with -3/2? You have not used it, why?
Well, I used 1.5 instead of 3/2