Equate what is inside cosine with
, base period and solve for x,



Hope this helps :)
For this case we have that by definition, the slope of a line is given by:

Two points are needed through which the line passes:

Substituting:
Rounding:

Answer:

It is right, because 36 is dividable by 6 and 9 (haha thats the funny number)
The area of the rectangle is simply width times length.
Hence, A = w*l = (6/5)*12 = 72/5 = 14.4 square inches (ANSWER)