Thread: Need help understanding what this question is asking.

The given function is:

f(x) =

It's asking for f'(x) = and says the answer will involve the variables t and x.

I found the derivative of the function using the Quotient Rule, but I don't understand the part where I need to take the limit which will include the variables t and x. Then it says taking the limit of that fractional expression gives f'(x) = _______. Wouldn't you have already found that in the first part of the question?

Originally Posted by ImaCowOK

The given function is:

f(x) =

It's asking for f'(x) = and says the answer will involve the variables t and x.

I found the derivative of the function using the Quotient Rule, but I don't understand the part where I need to take the limit which will include the variables t and x. Then it says taking the limit of that fractional expression gives f'(x) = _______. Wouldn't you have already found that in the first part of the question?

is one of the standard 'differentiation from first principles' formulae.