3. (6 points) Find whether functions below are continuous on their respective domains. (a) f(x) = z- 2x+3 on R. (b) f(x) = |x - 1| on R. (c) f(x) = = on (0, 00).4. (6 points) Compute the derivatives by using definition of the derivative. Using rules of differ- entiation is not allowed. (a) g(x) = = for x # 1 and a * -1. (b) f(x) = 3x3 + 2x3 + r + 1 for r ER