# Diffrentiation

• February 27th 2009, 12:03 PM
Raj
Diffrentiation
Quote:

1. I'm given a piece-wise function graph and i'm to determine the value(s) of x where the function is not differentiable. How would i do this?

2. y $=(x^2-4)/(x^2-2x-8)$. Determine the value(s) of x where the function is not differentiable.

3. At what points does the curve y $=x^3+3x^2-25x+1$ have horizontal tangents?
I just need to know how what I have to do in each situation
• February 27th 2009, 12:21 PM
arpitagarwal82
1) function will not be differentiable at point where its not continuous.

2) function is not differentiable for points $x^2 - 2x -4 = 0$

3) curve has horizontal tangent at point y' = 0
i.e. $3x^2 + 6x -25 = 0$