The day length in Manila, Philippines, varies over time in a periodic way that can be modeled by a trigonometric function.Assume the length of the year (which is the period of change) is exactly 365 days long. The shortest day of the year is December 21 , and it's 675.85 minutes long. Manila's longest day is 779.60 minutes long. Note that December 21 is 11 days before January 1 .Find the formula of the trigonometric function that models the length L of the day t days after January 1 . Define the function using radians.L(t)=□What is the day length on the People Power Anniversary (February 25 , which is 55 days after January 1) in Manila? Round your answer, if necessary, to two decimal places.minutes
Q. The day length in Manila, Philippines, varies over time in a periodic way that can be modeled by a trigonometric function.Assume the length of the year (which is the period of change) is exactly 365 days long. The shortest day of the year is December 21 , and it's 675.85 minutes long. Manila's longest day is 779.60 minutes long. Note that December 21 is 11 days before January 1 .Find the formula of the trigonometric function that models the length L of the day t days after January 1 . Define the function using radians.L(t)=□What is the day length on the People Power Anniversary (February 25 , which is 55 days after January 1) in Manila? Round your answer, if necessary, to two decimal places.minutes
Determine Amplitude: Determine the amplitude of the trigonometric function.The amplitude is half the difference between the longest and shortest day lengths.Amplitude = (Longest day length−Shortest day length)/2Amplitude = (779.60−675.85)/2Amplitude = 103.75/2Amplitude = 51.875 minutes
Determine Vertical Shift: Determine the vertical shift of the trigonometric function.The vertical shift is the average of the longest and shortest day lengths.Vertical shift = (Longest day length+Shortest day length)/2Vertical shift = (779.60+675.85)/2Vertical shift = 1455.45/2Vertical shift = 727.725 minutes
Determine Period: Determine the period of the trigonometric function.The period is the length of the year, which is given as 365 days.Period =365 days
Convert to Radians: Convert the period into radians.Since the period is one year and a full cycle in radians is 2π, the conversion factor is 2π radians per 365 days.Conversion factor = 3652π
Determine Horizontal Shift: Determine the horizontal shift of the trigonometric function.The shortest day is on December 21, which is 11 days before January 1. Therefore, the horizontal shift is 11 days to the right.Horizontal shift = 11 days
Write Trigonometric Function: Write the trigonometric function using the values found.The general form of a sinusoidal function is L(t)=A⋅cos(B(t−C))+D, where:- A is the amplitude,- B is the frequency (related to the period by B=Period2π),- C is the horizontal shift, and- D is the vertical shift.Using the values found:- A=51.875,- B=3652π,- C=11,- D=727.725.The function is A0.
Calculate Day Length: Calculate the day length on February 25, which is 55 days after January 1.Plug t=55 into the function L(t).L(55)=51.875×cos(3652π(55−11))+727.725L(55)=51.875×cos(3652π(44))+727.725Now calculate the cosine value and then the entire expression.
Perform Calculation: Perform the calculation for the cosine value and the entire expression.L(55)=51.875×cos(3652π×44)+727.725First, calculate the argument of the cosine function:(3652π)×44≈0.7596Now, calculate the cosine of this value and then multiply by the amplitude:cos(0.7596)≈0.7314 (using a calculator)51.875×0.7314≈37.951Finally, add the vertical shift:L(55)≈37.951+727.725L(55)≈765.676 minutesRound to two decimal places:L(55)≈765.68 minutes
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