已知x等于根号6减去根号5除以根号6加上根号5,y等于根号6加上根号5除以根号6减去根号5，求y/x-x/y的值

显示全部楼层 · 2011-9-26 21:22:22

x等于根号6减去根号5除以根号6加上根号5x=√6-√5/√6+√5x=(√6-√5)^2/(√6+√5)(√6-√5)x=(√6-√5)^2y等于根号6加上根号5除以根号6减去根号5y=√6+√5/√6-√5y=(√6+√5)^2/(√6+√5)(√6-√5)y=(√6+√5)^2y/x-x/y=y^2-x^2/xy=(√6+√5)^4-(√6-√5)^4/(√6-√5)^2(√6+√5)^2=((√6+√5)^2+(√6-√5)^2)((√6+√5)^2+(√6-√5)^2)/((√6-√5)(√6+√5))^2=(6+2√30+5+6-2√30+5)(6+2√30+5-6+2√30-5)/(6-5)^2=22* 4√30...

千问 · 2011-9-26 21:22:22

等于8√30...