Find Trig Eqn to model of velocity of breathing in L/sec

[FORK]

Here is a picture of my question, just click on it to enlarge it. I need the equation to be sin. Here is an example from another question of the format of the formula.

5sin30(x-1)+7

And here is the question

This is extremely urgent, please help out.

Thanks alot.

EDIT: Right click the picture, high view image to see the whole thing.

 

[tkhunny]

Didn't we just do one of these with a parabola?

For sin(x), you get a few adjustments: y(x) = a + bsin(c(x-d))

'a' will adjust the vertical zero. You have (0,0), so a = 0 and we have y(x) = bsin(c(x-d))

'd' will adjust the horizontal zero. Again, you have (0,0), so d = 0 and we have y(x) = bsin(cx)

'b' will adjust the amplitude. Normally, that would be '1', but you have only 0.85, so we have y(x) = 0.85*sin(cx)

'c' is the trickiest. This is the period adjustment. Normally, that would be \(\displaystyle 2\pi\). You have a period of 6. You can see this from noting that zero to maximum is 0.75. That's 1/4 of the period. This makes \(\displaystyle c = \frac{2\pi}{6} = \frac{\pi}{3}\).

There is just one more thing to wonder. This thing is going to go negative for 3 < x < 6. Is this the intent? You may have to rectify it or rethink it a bit.

Good luck. Please consider taking a math class or two (or five). You do seem to be working over your head, lately.

 

[FORK]

So then the equation is y(x)=.85sin(60(x))?

This is not exact but it does work, thank you.

And i am taking a math class, which is why I have all of these questions.. Grade 11 Math

 

[stapel]

i am taking a math class, which is why I have all of these questions

What the tutor meant, I believe, is that you need to drop this class and go back to a class which is prerequisite to this. Math is sequential and incremental, and you appear to be missing the necessary prerequisite material for this particular course. You need to go back and start over in a class where you won't be so "at sea", and then work your way up to this material. Until you have the mathematically-required foundations, you will very likely continue to be "lost" in your current course.

In other words, the tutor, based on many years' experience, was providing you with academic advising. Please seriously consider conferencing with your counsellor (guidance office?) regarding this issue!

Eliz.

 

[tkhunny]

So then the equation is y(x)=.85sin(60(x))?

Where did you get "60"? I'm confident I suggested \(\displaystyle \frac{\pi}{3}\).

Note: If your data are real, you have no expectation for an exact model.