1. Is the signal x(t) = cos2(2ft) periodic? If so, what is the period?

[rhushabh]

i finding it really difficult to know whether cos²(2pieft) is perriodic or not ?

 

[jeffrey samuel]

cos^2(x)=1-cos2x

cos2x is periodic and here only the amplitude gets scaled and so i guess the signal over all is periodic

cos^2(pift) here means f= frequency
t= time right?????

do post it soone

 

[manishanand14]

Hope it helps

 

[rhushabh]

cos^2(x)=1-cos2x

cos2x is periodic and here only the amplitude gets scaled and so i guess the signal over all is periodic

cos^2(pift) here means f= frequency
t= time right?????

its cos²(2pieft) = periodiic or not? Pls justify

 

[jeffrey samuel]

the scaling in the time in the angular frequency never hampers the periodicity it just alters the fundamental period of the signal

that is cos t is periodic

and also cos 2t is periodic

both have only 1 difference that is their fundamental period differs in both the case this can be applied here also

 

[syeda amna]

A function is periodic iff f(x)=f(x+p)
where p=smallest positive number.
x(t)=cos^2(x) is periodic with period pi. Go to wolframalpha.com to compute.

 

[rhushabh]

A function is periodic iff f(x)=f(x+p)
where p=smallest positive number.
x(t)=cos^2(x) is periodic with period pi. Go to wolframalpha.com to compute.

thanx
i got the point