To solve this problem you must apply the proccedure shown below:
You have the equatio h=7Cos(πt/3), therefore:
a) h=7Cos(πt/3)
Cos(πt/3)=h/7
Cos^-1(h/7)=πt/3
t=(3/π)(Cos^-1(h/7))
b)h=1
t=(3/π)(Cos^-1(1/7))
t=78.10
h=3
t=61.71
h=5
t=42.41
c) h=-1
t=93.79
h=-3
t=110.18
h=-5
t=129.47
