A function is continuous at a point when exists. This means that

It is differentiable at that point if the derivatives of the first and second terms in the piecewise function are the same at that point.For what value of k is f differentiable?

not even sure where to start i think i am on dealing with the second equation in this piecewise function

Note that you may not get the same k value for the continuity and differentiability cases...

Can you try these now and see what you get?

--Chris