The surface area s in square meters of a hot air balloon is

The surface area s (in square meters) of a hot air balloon is given by s(r) 4xr2 where ris the radius of the balloon (in meters) the radius ris increasing with time t (n seconds) according to the formula .t20 findthe surface areas of the balloon as a function of the time t S(t) (Type an expression using t as the variable. Type an exact answer, using x as needed. Use integers or fractions for any numbers in the expression. Simplify your answer) Enter your answer in the answer box. A 3:18 PM ca 11/30/2016

Solution

Plug r(t) = (7/8)t^2 into S(r) = 4r^2

S(t) = 4((7/8)t^2)^2

S(t) = (49/16) t^4