How do you solve the following?

1) What is the equation of the line tangent to the curve at x=-1. Graph what the curve and tangent will look like. f(x) = 4 - x^2 2) What is f'(x) of f(x) = 5x + (4/x)? Demonstrate both methods: techniques of differentiation and the definition of the derivative. 3) What is the derivative of the following functions: . f(x) = (1+ x - 4Vx)/x . f(x) = (1+x^2)(x (3/4) - x^-3)