Answer:
I will be able to tie the boat in 2 hours.
Step-by-step explanation:
f(t)=4sin(Ï€t/12)+7
At t=0, f(t)=7
we must find t in which f(t)=9, we can replace this and simply solve for t, also, we will be working with radians as units:
9=4sin(Ï€t/12)+7
2=4sin(Ï€t/12)
1/2=sin(Ï€t/12)
arc sin(1/2)=Ï€t/12
Ï€/6=Ï€t/12
12Ï€/Ï€6=t
2=t
So this is our number. To be sure of this we can replace 2 as t in out oiginal equation
f(2)=4sin(Ï€2/12)+7=9