The sinusoidal function f(x)=42sin(9x−π/10)+42 models the height, in centimeters, that a valve stem of the a tire is above ground x seconds after the tire begins to rotate. How long does it take the valve stem to complete one revolution? Enter your answer, rounded to the nearest hundredth of a second.
+36916 the 9 x part compresses the sinusoid wave from 2 pi to 2pi/9 sec = ~~.70 sec
