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