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Math Help - sin&cos

  1. #1
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    sin&cos

    I am given a graph and asked:

    let f(x)=sin(2pi x) and g(x)= cos(2pi x). Find a possible formula in terms of f or g for the graph.

    the graph: cos function
    period=1
    midline=-3
    amp=2

    the top of the wave starts at -1 and drops down to -5

    im not sure what the question is asking?
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  2. #2
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    Prove It's Avatar
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    Quote Originally Posted by Kate182 View Post
    I am given a graph and asked:

    let f(x)=sin(2pi x) and g(x)= cos(2pi x). Find a possible formula in terms of f or g for the graph.

    the graph: cos function
    period=1
    midline=-3
    amp=2

    the top of the wave starts at -1 and drops down to -5

    im not sure what the question is asking?
    OK, if the function is a cos graph, it's of the form

    y = a \cos(bx) + c,

    Where a is the amplitude, b = \frac{2\pi}{Period} and c is the mean value.

    So a = 2, b = 2\pi, c = -3

    Which means the function is

    y = 2 \cos (2\pi x) -3.

    Do you see that g(x) is contained in that graph?

    So we can write the graph in terms of g(x).


    y = 2g(x) - 3.
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  3. #3
    MHF Contributor Mathstud28's Avatar
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    Quote Originally Posted by Prove It View Post
    OK, if the function is a cos graph, it's of the form

    y = a \cos(bx) + c,

    Where {\color{red}|}a{\color{red}|} is the amplitude, {\color{red}|}b{\color{red}|} = \frac{2\pi}{Period} and c is the mean value.

    So a = 2, b = 2\pi, c = -3

    Which means the function is

    y = 2 \cos (2\pi x) -3.

    Do you see that g(x) is contained in that graph?

    So we can write the graph in terms of g(x).


    y = 2g(x) - 3.
    ....
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