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Some Trigonometry Questions

  1. Feb 5, 2009 #1

    Y = A cos(Bx+C)+K
    Y = A sin(Bx+C)+K
    I know what A,B,C, and K mean.. and I Also understand that I can get the Period from B..
    but, how can I use the information to draw the graph?
    I think I should use critical points, right? If so, what should I typically use?

    I dunno, I may face more problems, so I`m gonna post as soon as I face anything..

    Thank you in advance,

    well, I got an answer to the first two\three questions through Yahoo answers, but I still need an answer to the fourth one, please?

    Actually I think I could figure out how to draw the graph.. so thank you all,

    I think the topic should be closed.. (I got no more questions)
    Last edited: Feb 5, 2009
  2. jcsd
  3. Feb 5, 2009 #2


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    Gold Member

    Do you know that the standard y = sin x and y = cos x graphs look like? If so, then you just need to apply a set of transformations to obtain the graphs in 4.

    First consider the case where K=0, C=0 and B=1, so we have the graph of y = A sin x.

    How will this compare to the graph of y = sin x? We know that 'A' affects the amplitude of the graph. The standard graph has an amplitude of 1 unit. If we multply it by 'A', the new amplitude will be 'A'. So on a graph it will be very similar to the standard graph, with the difference being that instead of reaching a maximum of 1 and minimum of -1, it reaches a maximum of A and a minimum of -A.

    How will changing the other variables affect the graph?

    Basically, what i am saying is that to draw the graphs, consider what changing the values of A, B, C and K does (which you said you understand), and then simply do each transformation one step at a time, starting with the basic graph of y = sin x.
  4. Feb 5, 2009 #3
    danago, I`m really sorry..
    when I said the topic should be closed I didn`t notice that u replied

    thanx actually, n am sry I didn`t mean to be rude..
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