# Thread: sinusoidal equation

1. ## sinusoidal equation

in prince albert,the sun rises at 9:17 on december 21 and 4:35 on june 22. because there is no daylight savings time,the time the sun rises on any other date can be predicted from a sinusoidal graph with a period of 365 days.

write an equation that relates to the time the sun rises to the day of the year,and remember to show your work

2. your equation is in the form

$\displaystyle T = Asin (n(d-B)) + C$

$\displaystyle n = \frac{365}{2\pi}$

where d = day number and T is time of sunrise

you can use the points (172,9:17) & (355,4:35)

do you have any other information?

3. no,thats all they have given me,which is why i am stumped

4. maybe disregard B to give

$\displaystyle T = Asin (n(d)) + C$ then sub in points to find A & B.