Answer
a. 3147.75;
b. $7005.5
Work Step by Step
a. $P=\int ^{10}_{0} 400e^{0.03t}.e^{-0.08t}=400\frac{e^{-0.05t}}{-0.05}|^{10}_{0}=-8000(e^{-0.5}-1) \approx 3147.75 $
b. $A=e^{(0.08)10}\int^{10}_{0}400e^{0.03t}.e^{-0.08t}dt = e^{0.8}.400\int^{10}_{0}e^{-0.05t}dt=e^{0.8}.400.\frac{1}{-0.05}(e^{-0.05t}|^{10}_{0}) \approx 7005.5$
