Question

Find an equation that accurately models the curve.

Answer 1

Here is one way:
http://www.wolframalpha.com/input/?i=interpolate+%7B0.5%2C2.3%2C.6%2C1.75%2C0.4%2C2.3%2C.5%7D

And some info on various interpolation techniques -
http://en.wikipedia.org/wiki/Interpolation

Answer 2

If you want to use polynomial interpolation, see khan here - https://www.youtube.com/watch?v=sy132cgqaiU

Answer 3

What were those numbers you interpolated?

Answer 4

Just visual estimates based on your graph. You can substitute your own numbers if you know them.

Answer 5

Here are the points I used:

$$
{0.5,2.3,.6,1.75,0.4,2.3,.5,1.75}
$$

Answer 6

What are those numbers supposed to signify?the amplitudes?

Answer 7

yes, both at the max and at the min

Answer 8

You can add more points at the inflection points to get more accurate, I just added these

Answer 9

What points?

Answer 10

The points with dots would be your inflection points

Answer 11

To get an equation in hours, you'll need to solve something like polynomial interpolation -
http://en.wikipedia.org/wiki/Polynomial_interpolation#Constructing_the_interpolation_polynomial
https://www.youtube.com/watch?v=BJc0bQNRSo4

Answer 12

But it does not look the graph?