The water level varies from 12 inches at low tide to 52 inches at high tide. Low tide occurs at 9:15 a.m. and high tide occurs a
t 3:30 p.m. What is a cosine function that models the variation in inches above and below the water level as a function of time in hours since 9:15 a.m.?
<span>f(x)=20cos(bx)+c</span>
the value of c is 32... since the centre of the has been moved up 32 units
the minimum amplitude = 32 - 20 = 12 the maximum amplitude = 32 + 20 = 52
<span>f(x)=20cos(bx)+32</span><span>
if the curve takes 6 1/4 hours from low to high tides (9:15 am to 3:30 pm) then it will take 12 1/2 hours to complete a full cycle.
adjust the period by converting 12 1/2 hours to an angle measure.
