Question

If x^2/y^2+y^2/x^2=6 , (x, y z 0), then the value of (x – y) (x + y) + 2xy = m and the value of (x – y) (x + y) – 2xy = n. Find the value of mn. (1) 4 (2) 36 (3) 0 (4) 8

Answer 1

Step-by-step explanation:

x^4+y^4-6x^2y^2=0

x^2-y^2+2xy=m

x^2-y^2-2xy=n

mn= x^4-x^2y^2-2x^3y-x^2y^2+y^4+2xy^3+2x^3y-2xy^3-4x^2y^2

mn= (x^4-6x^2y^2+y^4)+0

mn= 0