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    May someone please explain this question to me?
    It seems straightforward but I don't understand it sorry.


    https://gyazo.com/c3ed58404f292f17280c4e115b20b3ff
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    Hi, you can think of this like y = bsinx a

    It's a graph of 2sinx that's been moved up by 1, so a=1 and b=2 (If you move it all down by 1 you'll see that it is a normal sin graph, but goes between -2 and 2, so has been stretched upwards by times 2)

    I don't know what the answer is, or if that's right, but that's what I'd put.

    Sorry if that explanation was horrible lol, but hope that helps
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    Uhmm the answer is correct , but I dont understand it Its probably because I need to learn the trigonometric graphs, I can do all the trigonometic equations and identities questions without knowing the trig graphs tho...


    What does the a and b supposed to be in the graph?

    Thanks!
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    (Original post by Jian17)
    Uhmm the answer is correct , but I dont understand it Its probably because I need to learn the trigonometric graphs, I can do all the trigonometic equations and identities questions without knowing the trig graphs tho...


    What does the a and b supposed to be in the graph?

    Thanks!
    You are right - you do need to learn the shapes of the trig graphs. But this is really about linear transformation of a function. y = a + bsinx is a linear transformation of y = sinx with a vertical stretch factor of b and a vertical shift of a.
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    Oh okay, no worries!

    The +a is going to translate the graph vertically (so +1 will move the whole thing up by 1)

    bsinx means that you'll have a sinx graph that has been stretched by b (so 2sinx means times all the y coordinates by 2)

    Use BIDMAS, so you have to times the Y coordinates by 2 first and then shift the whole graph up by 1.

    Sorry if this isn't making too much sense, someone much better at explaining than me should see this soon!
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    (Original post by Jian17)
    May someone please explain this question to me?
    It seems straightforward but I don't understand it sorry.


    https://gyazo.com/c3ed58404f292f17280c4e115b20b3ff
    I got 1+2sinx

    The way I did it was by looking at the graph . I used the coordinate (0,1) to find a , then use coordinate (1/2pi,3) to find the value of b .
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    (Original post by HelloImCool)
    I got 1+2sinx

    The way I did it was by looking at the graph . I used the coordinate (0,1) to find a , then use coordinate (1/2pi,3) to find the value of b .
    I don’t know if this is the best way to approach it though. I just used simple algebra

    I self quoted myself sorry
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    Thanks everyone for their help! I understand it better now, I will ask my teacher to explain it to me too when i can just to make sure i understand the concept tho
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    (Original post by HelloImCool)
    I got 1+2sinx

    The way I did it was by looking at the graph . I used the coordinate (0,1) to find a , then use coordinate (1/2pi,3) to find the value of b .
    Why did you use the coordinate 1/2pi,3 to find b?? I can see why you used 0,1 but the other one :s
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    (Original post by Jian17)
    Why did you use the coordinate 1/2pi,3 to find b?? I can see why you used 0,1 but the other one :s
    You’re over complicating it.

    y = sinx is a periodic function with a minimum value of -1 and a maximum value of +1. The difference between the two is 1 - (-1) = 2.

    The transformation of y = sinx shown in the diagram is a periodic function with a minimum value of -1 and a maximum value of 3. The difference between the two is 3 - (-1) = 4. So the stretch factor b is .....
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    (Original post by Jian17)
    Why did you use the coordinate 1/2pi,3 to find b?? I can see why you used 0,1 but the other one :s
    3=1+b(sin(90)) —> sin 90 =1

    3=1+b
    2=b
 
 
 
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