a,b,c and d are positive integers. Quantity I: `'a':-((a+d)^(2)-(a-d)^(2))/(8ad(a+d)^(2))=1` Quantity II: `'b'((b+d)^(3)-(b-d)^(3))/((d^(2)+3b^(2)))=(1)/(8d)` Quantity III: `'c':-(sqrt(c+d)+sqrt(c-d))/(sqrt(c+d)-sqrt(c-d))`