Question

已知x=2分之1(√5+√3),y=2分之1(√5-√3),求x2-xy+y2和y分之x+x分之y的值.

Answer 1

xy= 1/2 x+y=√5 x^2-xy+y^2=(x+y)^2-3xy =5-3/2=7/2

x/y+y/x=(x^2+y^2)/xy=[(x+y)^2-2xy]/xy=(x+y)^2/xy-2=10-2=8