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Secondary IV • 27d
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I dont know how to find my paramater b by finding the period

Mathematics
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Explanations (1)

  • Explanation from Alloprof

    Explanation from Alloprof

    This Explanation was submitted by a member of the Alloprof team.

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    Team Alloprof • 27d

    Salut!


    You can find the parameter b by finding the period of the function:

    image.png


    and using this formula:

    image.png


    The period of a function is the interval in x that it takes to complete a cycle. In your exercise, you have a complete cycle here:

    image.png


    So the period is:

    $$p=\frac{10 \pi}{3}-\frac{ 2\pi}{3}=\frac{8\pi}{3}$$


    Using the previous formula, we can then find the absolute value of the parameter b:

    $$p=\frac{2\pi}{|b|}$$

    $$\frac{8\pi}{3}=\frac{2\pi}{|b|}$$

    $$|b|=2\pi \times \frac{3}{8\pi}$$

    $$|b|=\frac{2\times 3}{8}$$

    $$|b|=\frac{6}{8}=\frac{3}{4}$$


    Since the sign of b does not change the shape of the curve, the simplest thing is to choose the positive value.

    $$b=\frac{3}{4}$$


    There you go! :D Here's a sheet on this concept that presents similar examples: Finding the Rule of a Cosine Function | Secondaire | Alloprof


    Let us know if we can help you with anything else! :)

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