Adding sine functions

  • #1

Main Question or Discussion Point

What happens when you add two sin functions for example:
y=sin(x) + sin(2x)

***additional questions***
how about adding more than two funtions such as
y=sin(x+p/2)+sin(2x+p/2)+sin(3x+p/2)+sin(4x+p/2)+sin(5x+p/2)+sin(6x+p/2)+sin(7x+p/2)
 

Answers and Replies

  • #2
phinds
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What do you mean what happens? You get the sum. Draw the graph and have a look. It looks cool.

Do you mean, can you reduce the answer in some neat way? I don't think so, but I could be wrong.
 
  • #3
What do you mean what happens? You get the sum. Draw the graph and have a look. It looks cool.

Do you mean, can you reduce the answer in some neat way? I don't think so, but I could be wrong.

As in what happens to the amplitude, period, phase shift etc,
 
  • #4
phinds
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Jeez, guy ... if you can't see in your head what it does, draw the graph and it will become obvious what it does.
 
  • #5
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This may help:

sin(a)+sin(b)=2(sin(.5)(a+b) X cos (.5)(a-b))
 
  • #6
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I don't think you can get some universal answer for this, because your sum is a new function which is not a simple sinusoid anymore, although it is periodic. So it doesn't make sense to speak of an amplitude or a phase shift, at least not in the same sense as in with pure sinusoids.

This is your function (y = sinx + sin2x)
banAP.png
 
  • #7
phinds
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I don't think you can get some universal answer for this, because your sum is a new function which is not a simple sinusoid anymore, although it is periodic. So it doesn't make sense to speak of an amplitude or a phase shift, at least not in the same sense as in with pure sinusoids.

This is your function (y = sinx + sin2x)
banAP.png
Yeah, that's what I was trying to get HIM to do. How's he going to learn if you do it for him?
 
  • #8
Char. Limit
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If you want to have a bit of fun, try adding sin(x) + sin(2x)/2 + sin(3x)/3 and so on, and see what shape you get.
 
  • #9
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Yeah, that's what I was trying to get HIM to do. How's he going to learn if you do it for him?
Ah, sorry, didn't realize you were trying to educate him that way. Let's hope he'll still learn, tho.
 
  • #10
thx for help everyone...hopefully i will be able to return the favour sometime in the near future... I am new to the site and atm it is mostly welcoming so once again thx :)
 

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