In Reply to: Help on Frequency and Period posted by Michelle on 03/15/00 at 4:58 PM:
: Hi all!Could anyone please help me with this question.How do you find the period and frequency of 5+5sin(20t)?Any help would be greatly appreciated.Thanks!
5+5*sin(20t) is a wavform whose excursions run from zero to +10. The normal definition of a sine function is that the argument, shown here within the parenteses, is "omega tee" where we will use the English letter W to represent the Greek letter omega.
The W in 5 + Sin(Wt) is called the radian frequency and equals 2*pi*f where pi = 3.14159... and f is the frequency in Hertz (formerly cycles per second).
In this case, W = 20 radians per second for which f = W /2 / pi = 20 / 2 / 3.14159... = 3.18309... Hz. This is the frequency of 5 + 5 * Sin (20t).
The period is the reciprocal of the frequency. The period is the time which will elapse during the waveform's excursion through one complete cycle of variation. In this case, the period is 1/3.18309.. Second = 0.314159.. Second.
The DC term, if we may call it that, is +5. This does not have any effect on the frequency or the period.
Good luck.
John Dunn - President
Ambertec, Inc.
ambertec@ieee.org