I need help with this. Mostly just 2a and 2b.

2a. A(t) = π(70 + 6t)^2 (Let t = 2 hours)

     A(2) = π(70 + 6(2))^2 = 6724π

     Now let t = 0 hours (result from part 1)

     A(t) = π(70 + 6(0))^2 = 4900π

     Average rate = 6724π - 4900π/2-0 = 912π

     912π area covered per hour

2b. Let t = 1/2 hours, A(t) = π(70 + 6(1/2))^2 = 5329π,

     Let t = 0 hours - result from last time was 4900π,

     Average rate =  5329π - 4900π/1/2 - 0 = 858π

     858π area covered per hour

Sure! What do you need help with?