Question

Please help I don't understand.

Answer 1

Part A

$A(p) =2p \pi \\ p(t) = 6t \\ A(p(t)) = 2 \times 6t \times \pi = 12t\pi$

Part B

$A(p(8)) = 12 \times 8 \times \pi = 301.44 \: u {}^{2}$