#find phase shift in sin graph

22 messages · Page 1 of 1 (latest)

alpine plover
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i wanted to find the sin function from this graph just as practice. i believe i got everything correct in my final answer except the phase shift. can someone please help finding the phase shift?

remote cargoBOT
alpine plover
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my phase shift is:
pi/2 + 1
because the graphs first maximum is at 1, instead of pi/2

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but i seem to be finding that incorrectly

alpine plover
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i randomly guessed that its actually -1/4 but i dont know why

crimson schooner
alpine plover
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ohhhhh right

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so i believe i didnt provied enough information in the graph when i made the question

crimson schooner
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there's enough information

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You need the period first, and from that you can get the phase shift

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@alpine plover

alpine plover
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if i do

2pi/3 * asin(1)

i believe i should get the theta value of the function with no phase shift

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and then the desired phase shift would be 1 minus that

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lemme check

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no

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i just have to find what x value yields 1 in sin(2pi/3 x)

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sin(2pi/3 x) = 1
2pi/3 x = arcsin(1)
2pi/3 x = pi/2
x = (pi/2)/(2pi/3)
x = (pi/2)(3/2pi)
x = 3pi/4pi
x = 3/4

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and we need to shift right by 1 - 3/4

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f(x) = 67/56 * sin(2pi/3 * (x - 0.25)) -53/56

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amazing

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thank you a lot 🎑

midnight urchin
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.close