化简,求值:(1/x+y)+(1/x-y)除以(2x/x^2-2xy+y^2)其中x=根号3,y=负根号2
问题描述:
化简,求值:(1/x+y)+(1/x-y)除以(2x/x^2-2xy+y^2)其中x=根号3,y=负根号2
答
(x-y+x+y)/(x^2-y^2)*((x-y)^2/2x)
=2x/(x-y)(x+y)*((x-y)^2/2x)
=(x-y)/(x+y)
x=根号3,y=负根号2
原式=(根号3+根号2)/(根号3-根号2)
= (根号3+根号2)^2/(3-2)
=(3+2+2根号6)/1
=5+2根号6