Let f(x) be the function 1/[x+12] . Then the quotient [f(4+h)-f(4)]/h

Question

can be simplified to for: -1/[ah+b]

a=
b=

Answer 1

[1/(4+h+12) - 1/(4+12) ] / h

[ 1/(16+h) - 1/16 ] / h

[ 16 - 16-h ]/[(16+h)(16)h]

-h / [(256+16h)h]

-1 / [16 h + 256]

Answer 2

Plug and chug :)