Decide whether the following statement is true or false. If it is true explain why; if it is false also explain why:
There is at least one root of f(x) = x²-2x-√x-1 in the interval (2,5).

(b) For the function f(x) in (a), find f'(x) by using the limit definition of the derivative.
(c) For the function f(x) in (a), find f'(x) by using the formulas of the derivative.