Question

Given y=8/(x+1) , express approx change in y in term of m when x changes from 3 to (3-m) where m is a small value.

Answer 1

Simply plug 3 into y aswell as 3-m.
y(3)=8/(3+1) - y(3-m)=8/((3-m)+1)
8/(3+1)-8/((3-m)+1)=?

Answer 2

first off \(\frac{8}{3+1}=2\)

Answer 3

so you are looking at
\[\frac{8}{3-m+1}-2\] i.e.
\[\frac{8}{4-m}-2\]

Answer 4

or if guess if you want "from 3 to 3 - m" you can write
\[2-\frac{8}{4-m}\]and if you really want you can do the subtraction and get
\[\frac{2(4-m)-8}{4-m}=\frac{8-2m-8}{4-m}=\frac{-2m}{4-m}=\frac{2m}{m-4}\]

Answer 5

But the answer is m/2 ??