I've been struggling in this sound wave question for more than 30min, can someone help me please?

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1 Answer
Sep 29, 2017

a. The period is #3#
b. The amplitude is #1/4#
c. Sorry, I wasn't able to explain clearly. Please help.

Explanation:

a. The period of trigonometric functions are as follows.
#f(x) = sin(aθ) or f(x) = cos(aθ)# -> The period is #(2pi)/a#
#f(x) = tan(aθ) # -> The period is #(pi)/a#

In the equation #y=1/4cos((2pi)/3theta)#, #a#=#(2pi)/3#,
so the period is #(2pi)/((2pi)/3)=3#.

b. The amplitude is the maximum absolute value of the wave.
For #sin# or #cos# functions, the amplitude is the coefficient before
the trigonometrics.Therefore the amplitude for #y=1/4cos((2pi)/3theta)# is #1/4#.

c. The equation of a function is a relationship between the variables.
For example, #y=2x# is an equation, and this means #y# is
proportional to #x#.

The equation #y=1/4cos((2pi)/3theta)# is a trigonometric function.
If you prot #theta# and #y# on a plane you will see a wave-shaped graph.