Question

Write the value for which f(x)=|x-5| is not differentiable in R. Please write answer as 4 marks.

Answer 1

Answer:

is to check the continuity of f(x) at x=3, and the other is to check whether f(x) is differentiable there. First, check that at x=3, f(x) is continuous. It's easy to see that the limit from the left and right sides are both equal to 9, and f(3) = 9. Next, consider differentiability at x=3.