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Re: How can I reduce the frequency of a sine wave tia

  • To: mathgroup at smc.vnet.net
  • Subject: [mg104726] Re: [mg104714] How can I reduce the frequency of a sine wave tia
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Sun, 8 Nov 2009 06:44:08 -0500 (EST)
  • Reply-to: hanlonr at cox.net

Modulate and filter the signal

a = Sin[f1* x];

b = Cos[(f1 + f2)*x];

c = -2*Select[
    a*b // TrigToExp // ExpandAll,
    FreeQ[#, f1, 4] &] // FullSimplify

sin(f2 x)


Bob Hanlon

---- Rick T <ratulloch at gmail.com> wrote: 

=============
Greetings All

I have the example below which produces 10 cycles
a = Sin[10 x]
Plot[a, {x, 0, 2 Pi}]

What Type of signal would I need to add/multiple/divide to reduce it's
signal/frequency to 5 cycles?  I know I can just change the number 10
to 5
but I need to combine it with another signal.  what mathematical
operation/signal do I need to use.

tia sal2



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