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