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Math Help - Finding the formula to a graph

  1. #1
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    Exclamation Finding the formula to a graph




    Please help me find the formula to these two graphs. Also show your steps and work to how you found the formulas. I already know how to find the amp and midline. What I am having problem is finding the "c" in the formula y = A sin (Bx + C) + h.

    Thank you so much!
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  2. #2
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    1) It apears you MUST use the SINE functions. Great. What are the characteristics of the function y = sin(x)?

    1a) Starts at zero: 0 = \sin(0)
    1b) It first goes in the positive direction.
    1c) Period is 2\pi
    1d) Amplitude is 1

    2) Now let's take a look at your graph.

    2a) Starts at zero: 0 = \sin(0) - Good.
    2b) It first goes in the positive direction. - Good.
    2c) Period is 2\pi - Nope. We have \frac{\pi}{14} I think. The drawing is not real clear.
    2d) Amplitude is 1 - Nope. It appears to be 0.80

    3) Okay, so how do we fix it?

    3a) Starts at zero: 0 = \sin(0) -- y = sin(x)
    3b) It first goes in the positive direction. -- y = sin(x)
    3c) Period is 2\pi -- \frac{2\pi}{\frac{\pi}{14}}\;=\;28. -- y = \sin(28x)
    3d) Amplitude is 1 -- y = 0.80\cdot \sin(28x)

    I think we're done.
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  3. #3
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    Thank you so much for helping me with part 1, it was an excellent explanation . To be honest, I don't know where to start at for part 2. Is there such a formula for it? The lines does not seem to be heading up/down at a constant pace and makes steep slopes at the point above the midline. So can you confirm that this has no formula or is there a formula for it?
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  4. #4
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    second graph looks like an attempt to sketch this ...
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