The radius r, in inches, ofa spherical balloon is related to the volume V by (3V T(V)= 3 E. Air is pumped into the balloon so the volume after 1' seconds is given by V(t) = 18 + 141'. a. Find an expression for the composite function r (V (t)). To enter 17:, type pi. To enter a cube root, use a fractional 1/3 exponent, type \"(1 [3)\". r (V (0) = b. What is the exact time in seconds when the radius reaches 14 inches