
Calculus Calculus Math Forum 
 LinkBack  Thread Tools  Display Modes 
August 19th, 2009, 09:06 PM  #1 
Newbie Joined: May 2009 Posts: 20 Thanks: 0  periodic/not periodic functions application to electronics
one of the following functions is periodic and the other is not: f(t) = cos(10(pi)t)+3sin(4(pi)t) g(t) = cos(10t)+3sin(4(pi)t) which function is peridic? what is the fundamental period of the function? which is not periodic and why isnt it? 
August 20th, 2009, 04:36 AM  #2 
Member Joined: Jul 2009 Posts: 34 Thanks: 0  Re: periodic/not periodic functions application to electronics
The functions sin(at) and cos(at) are periodic and their period is . If we look at , then we see that the cosine has period , and that the sine has period . Which means that for every 5 periods of the cosine, there are 2 periods of the sine, and hence it's also 1 period of the sum, f(t). The length of this period is then 1. But if we look at , the period of the cosine is and that of the sine is . In this case, we can't say that a whole number of periods of the cosine is equal to a whole number of periods of the sine. Hence we can't point out a period for the sum of them, g(t). 

Tags 
application, electronics, functions, periodic, periodic or not 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
periodic functions  hoyy1kolko  Algebra  2  January 10th, 2011 01:28 PM 
Periodic Functions  Sarah112  Algebra  1  November 13th, 2010 12:56 PM 
3 Questions on Periodic Functions  Tetra  Algebra  20  January 24th, 2010 01:44 AM 
difference of periodic functions  ElMarsh  Real Analysis  3  October 18th, 2009 03:49 PM 
Periodic Functions  Sarah112  Real Analysis  0  December 31st, 1969 04:00 PM 