# Using the limit definition, how do you find the derivative of #f(x)=4+x-2x^2#?

##### 1 Answer

Jan 3, 2017

Please see the explanation.

#### Explanation:

The limit definition of the derivative is:

We are given that

Substitute the right sides of equations [3] and [2] into equation [1]:

Combine like terms in the numerator:

There is a common factor of h in the numerator and denominator:

Now it is ok to let