I always have difficulties with fractions...
Find the derivative of f(x) = (x/x+1) - 3
I usually break it down to f(x) = x/x +x/1 -3
f'(x) = 1 + 1
I know that's not right...please help.
You can only break up a fraction if the added terms are on top, not bottom.
So while , it's not true that .
So we can't use that kind of techniue in this particular situation.
What you want to do here is apply the quotient rule, which basically says that if and are differentiable functions, then .
In your case, is the top of the fraction and is the bottom, .
So and .