Question

if x is equals to under root 5 + under root 2 upon under root 5 minus under root 2 and Y is equals to under root 5 minus under root 2 upon under root 5 + under root 2 show that 3 a square + 4 AV minus 3 b square equal to 4 + 56 upon 3 under root 10

Answer 1

X = √(3+1)/√(3-1)

=√4/√2

=√2

Y = √(3-1)/√(3+1)

=√2/√4

=1/√2

X^2 + XY - Y^2 =

(√2)^2 + (√2)(1/√2) -(1/√2)^2

=2+1 -1/2

= 3 + 1/2

= 7/2