What is the fundamental period of 2 cos (3x)?

2 Answers
Apr 24, 2015

The fundamental period of #cos(theta)#
is #2pi#
That is (for example) #cos(0) " to " cos(2pi)#
represents one full period.

In the expression #2 cos(3x)#
the coefficient #2# only modifies the amplitude.

The #(3x)# in place of #(x)#
stretches the value of #x# by a factor of #3#

That is (for example)
#cos(0) " to " cos(3*((2pi)/3))#
represents one full period.

So the fundamental period of #cos(3x)# is
#(2pi)/3#

Apr 24, 2015

#(2pi)/3#

Period of cos x is #2pi#, hence period of cos 3x would be #(2pi)/3#, which means it would repeat itself 3 times between 0 and #2pi#