Prove that a polynomial function f is continuous

Given an example of a function which is continuous at x =1 but not differentiable at x=1 .

The polynomial is

Find the value of k, so that the function f is continuous at the indicated point. f(x)={{:((kappacosx)/(pi-2x)",","if "x ne (pi)/(2),,),(,,,"at " x=(pi)/(2)),(3",", if "x=(pi)/(2),,):}

Prove that the identity function f(x) = x is continous

Prove that F = ma.