Answer:
-3-4x
Step-by-step explanation:
<h2>○=> <u>Correct option</u> :</h2><h2>

</h2><h3>○=> <u>Steps to derive correct option</u> :</h3>
We know that :

So, let the diameter of this circle be x.
Which means :





Thus, the radius of the circle Robert drew = 6 m
Since the circle in option B has a radius of 6 m, it is the circle Robert drew.
▪︎<em>Therefore, the correct option is (B)</em>
ANSWER

EXPLANATION
The frequency of a wave function refers to the number of times the graph repeats its cycle within the interval [0,2π]
We can observe explicitly from the graph that the frequency is half.
The period of the given function is 4π


Hence the frequency is half.
Its A you just have to count the lines and say the numbers 1-4