Could someone please help me with this?

Question

Calculate the instantaneous rate of change of f <note: f(x)=(x-6)/(x+6)> at x=6.

Answer 1

why the <note>? Just say what f(x) is. You can use the quotient rule if you want, but note that

f(x) = (x-6)/(x+6) = 1 - 12/(x+6)
so,
f'(x) = 12/(x+6)^2

f'(6) = 12/12^2 = 1/12

Answer 2

OH okay thank you so much!