Answer:
[tex]2\pi\ seconds=6.28\ seconds[/tex]
Step-by-step explanation:
Trigonometric Functions
The trigonometric functions have a cyclic behavior, which means they perform a full cycle and then do it all again in their whole domain. If we know that
sinx=0
we can use the inverse sine function to know the values of x. In this case, all angles whose sine is 0.
X=0 is the trivial solution, but given the repetitive nature of the sine, we know the next cycle will repeat the same value. Each cycle occurs every [tex]2\pi[/tex] units of x, so the solution is
[tex]x=0+2k\pi[/tex]
being k any integer number, positive or negative
The height of the tip of the blade (in feet) of our windmill has a motion described by the equation
[tex]h(x)=-14sinx+18[/tex]
Let's start one cycle by setting x=0, so the initial value of h is
[tex]h(0)=-14(0)+18=18[/tex]
The very next cycle will be when h=18 again
[tex]-14sinx+18=18[/tex]
Or
sinx=0
Which next solution is
[tex]x=2\pi[/tex]
So, it will take to make a full rotation for one blade a time of
[tex]2\pi\ seconds=6.28\ seconds[/tex]