How do I use sine as a function to figure out the amount of daylight (in minutes) there will be on any given day of the year in San Francisco? (longitude: 122 degrees, 26 m W & latitude: 37 degrees, 46 m N)
2007-04-21 12:21:39 · 2 answers · asked by soccerlover39 1 in Science & Mathematics ➔ Mathematics
Its not a simple sine function but it can be done. You need to know your latitude and the declination of the Sun. You latitude is easy, declination is more complicated but an excellent approximation is pretty simple. The declination in degrees is:
D = 23.5 sin(n * 360/365)
Where n is the number of days since last March 21st.
Call your latitude in degrees L.
The minutes of daylight is: H = 8*acos(-tan(L)*tan(D))
Just make sure your arc cosine evaluates in degrees.
2007-04-21 12:33:35 · answer #1 · answered by Pretzels 5 · 0⤊ 0⤋
Someone else asked this about two hours ago.
Check the back question log.
2007-04-21 21:28:19 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋