# How do you find the differentiable points for a graph?

##### 1 Answer

Differentiability roughly indicates smoothness of the graph, so if there is a sharp corner or a discontinuity, then it would not be differentiable there. If there is a vertical tangent line, then it would not be differentiable there even though the graph is smooth.

Thus: to find the differentiable points on a graph, you can look for points where the graph is smooth without a gap, a corner, or a vertical tangent line.