Chapter 3.5, Problem 36P

To determine

(a)

To find $D\left(40\right)$, $D^{\prime }\left(40\right)$ where $D\left(t\right)$ is the approximation of number of hours of daylight in Paris with $t$ being the number of days.

$D\left(t\right)=4\cos \left(\frac{2\pi }{365}\left(t-172\right)\right)+12$

To determine

(b)

To find $D\left(172\right)$, $D^{\prime }\left(172\right)$ where $D\left(t\right)$ is the approximation of number of hours of daylight in Paris with $t$ being the number of days.

$D\left(t\right)=4\cos \left(\frac{2\pi }{365}\left(t-172\right)\right)+12$