differentiable functions

Question

Show that the function g(x) = (√( 8x − 1))^3 is not differentiable at x=1/8 . Do not rely on the graph of g(x).

Answer 1

g(x) is not defined for when x<1/8 because you cannot take the square root of a negative value.

Therefore g(x) is not continuous or differentiable at x=1/8