# Derivative: find a slope of tangent line=square root of 4-5x when x=-1 ?

##
I want to know which formula will work to find slope in derivative and what will be its answer.

I want to know which formula will work to find slope in derivative and what will be its answer.

##### 1 Answer

Feb 17, 2018

#### Explanation:

For square roots, I like to change the notation to exponential notation rather than radical notation:

So now we have

Change back to radical notation

Substituting x=-1 gives us