# Find sine function through two points.

• May 17th 2011, 02:09 PM
ninasukkah
Find sine function through two points.
Write an equation of the form https://webwork.wpi.edu/webwork2.4.7...bdad646821.png whose graph is the sine wave shown above. The curve goes through the points https://webwork.wpi.edu/webwork2.4.7...e9e49f4bf1.png and https://webwork.wpi.edu/webwork2.4.7...f7a8f79751.png.

I forget how to do this. :(
• May 17th 2011, 02:16 PM
pickslides
There is more than one possible solution here that I can see.

I'm happy to help but we need to focus on the one you require. First thing to do is draw a sine function that goes through these 2 points.

I have one in mind. It has the y-intercept at (0,4) and half way through the cycle returns to (2,4). Can you draw a picture of that?

If so what is the period of the function?
• May 17th 2011, 02:19 PM
SpringFan25
You need to show us the actual graph, there are many many many many sine curves which pass through those two points (example: $y = sin(0.5 \pi x) + 4$).

Is the method not in your class notes or text book?

Edit pickslides was faster :P
• May 17th 2011, 02:29 PM
ninasukkah
I can't add an image, I don't know why but it doesn't show.
• May 17th 2011, 02:39 PM
ninasukkah
• May 17th 2011, 03:52 PM
pickslides
Thanks for the link, the question now has only one solution. Looking at the graph, what is P the period?

You can then find B given $\displaystyle \frac{2\pi}{B} = P$
• May 17th 2011, 09:06 PM
Soroban

There is still an infinite number of possible functions.

Here's one of them: . $f(x) \:=\:-3\sin(\pi x) + 4$