Answer:
The frequency of the given sinusoidal graph is 4.
Step-by-step explanation:
The frequency of a sinusoidal graph is the number of cycles it completes in the interval 0 to 2π radians.
From the given sinusoidal graph it is noticed that the the graph complete its one cycle in the interval 0 to
.
If the complete its one cycle in
, then the number of cycles completed by the graph in the inteval 0 to 2π is



Therefore the frequency of the given sinusoidal graph is 4.
Answer:
Mrs. Stern washed more
laundry still needs to be washed.
Step-by-step explanation:
Total amount of laundry: 


of the laundry still needs to be done.
Mrs. Stern washed
of the laundry.
Her son washed
of the laundry.
Mrs. Stern washed more laundry than her son.

Then using trygonometric table or a graph we read that:

Period of cosinus function = 2π
So the last answer is