To find an equation for the temperature, D, in terms of t, we can use the properties of a sinusoidal function to model the temperature variation over the day.
Given:
High temperature: 80 degrees
Low temperature occurs at 5 AM (t = 5)
t is the number of hours since midnight
Let's assume a sinusoidal function of the form:
D = A * sin(B * t + C) + Dc
where:
A represents the amplitude (half the difference between the high and low temperatures)
B represents the frequency (how many cycles occur over a 24-hour period)
C represents the phase shift (how much the function is shifted horizontally)
Dc represents the vertical shift (the average temperature throughout the day)
We can determine the values of A, B, C, and Dc based on the given information.
Amplitude (A):
The amplitude is half the difference between the high and low temperatures:
A = (80 - 50) / 2
= 30 / 2
= 15 degrees
Frequency (B):
Since we want the temperature to complete one cycle over a 24-hour period, the frequency can be calculated as:
B = 2π / 24
Phase Shift (C):
Since the low temperature occurs at 5 AM (t = 5), the function should be shifted horizontally by 5 hours. To convert this to radians, we multiply by (2π / 24):
C = 5 * (2π / 24)
Vertical Shift (Dc):
The average temperature throughout the day is the midpoint between the high and low temperatures:
Dc = (80 + 50) / 2
= 130 / 2
= 65 degrees
Now we can put all the values together to obtain the equation for the temperature, D, in terms of t:
D = 15 * sin((2π / 24) * t + (5 * 2π / 24)) + 65
Simplifying further:
D = 15 * sin((π / 12) * t + (π / 12)) + 65
Therefore, the equation for the temperature, D, in terms of t is:
D = 15 * sin((π / 12) * t + (π / 12)) + 65.