Question

if x+y = √11 , x^2=y^2 =5 find the value of xy ?

Answer 1

square both sides

(X + Y)² = (√11)²

X² + Y² +2XY = 11

put value of X² and Y²

5 + 5 + 2XY = 11

2XY = 11 - 10

2XY = 1

:. XY = 1/2