I wonder whether the answer for both a and b should contain a negative sign or not?

1. For the function f (x) = 3 Vx - 4 f(x) - f(a) (a) Use the definition of the derivative f'(a) = lim r - a to find a formula for the derivative of f at a. (b) Use the equivalent definition of the derivative f'(a) = lim flat h) - f(a) h -0 h to find a formula for the derivative of f at a