Which interval does the shaded area represent?

Question

(The picture shows the first quadrant with the graphs of y=x^2 and y=cosx; the shaded area is a rectangle with the top right corner being the intersection of the functions and the bottom right corner being the origin)

The choices are:
a. 0.46<R<0.5
b. 0.54<R<0.58
c. 0.42<R<0.46
d. 0.5<R<0.54
e. 0.58<R<0.62

Any help or ideas to solve it is appreciated, Thank You!

Answer 1

the two functions intersect at
x = ± .824132

I have no idea what R is supposed to be