Determine whether the following functions are continuous on R: 21 - 7x x - 3 t - 27 t-3 o f(x) = g(t) = = h(u) = of(x)= = t# 3 t = 3 -3x + 7 u 3 -2 u > 3 X x < 0 x 0x 1 X x > 1 Find a, b such that the function f(x) = is continuous everywhere. x + 1 ax+b 3x x < 1 1