Boyle's law gives the expression :
Boyle's law may be represented as
1.[dp/dv]T=K/V
2.[dp/dv]T=-K/V
3.[dp/dv]T=-K/V
4.[dp/dv]T=K/V^2
In the adjoining figure, ABCD and PQRC are rectangles, where Q is the midpoint of AC. Then DP is equal to