In a stadium a running track of 440 m is to be laid out enclosing field. The shape of track is a rectangle with a semi-circle at each end. They want to keep maximum area of rectangular portion.

Given answer of the question:
If a shows area of field (rectangular portion), the function of A in terms of x will be :

Options

A. `x((440-x)/pi)`
B. `1/pi (440-x^2)`
C. `(220-2x^2)/pi`
D. `1/pi(440x-2x^2)`

Answer

D