7. Use the limit definition of the derivative to find f'(x). Then find the equation of the tangent line at x = 1. f(x) = Vr + 3 8. Given that f(x) is continuous at x = 0, is f(x) differentiable at a = 0? (If yes, find f'(0) using the definition of the derivative. And if no, show why using the definition of the derivative.) f(x) VI,