Answer
For $t=0$, $E=5$
For $t = 0.03$, $E=1.545$
For $t = 0.06$, $E=-4.054$
For $t = 0.09$, $E=-4.054$
For $t = 0.12$, $E=1.545$
Work Step by Step
We substitute each of the five values of $t$ in the formula to find the value of E for each value of $t$:
For $t=0$,
$E = 5 \cos 120\pi(0)=5 \cos 0\pi=5\cos 0=5(1)=5$
For $t = 0.03$,
$E=5 \cos 120\pi(0.03)=5\cos 3.6\pi=5(0.3090)=1.545$
For $t = 0.06$,
$E=5 \cos 120\pi(0.06)=5\cos 7.2\pi=5(-0.8090)=-4.054$
For $t = 0.09$,
$E=5 \cos 120\pi(0.09)=5\cos 10.8\pi=5(-0.8090)=-4.054$
For $t = 0.12$,
$E=5 \cos 120\pi(0.12)=5\cos 14.4\pi=5(0.3090)=1.545$
