已知a=20002000/20012001,b=20012001/20022002 c=200220002/20032003,比较a,b,c的大小.
问题描述：
已知a=20002000/20012001,b=20012001/20022002 c=200220002/20032003,比较a,b,c的大小.
答
已知x=1/2 y=1/3 z=1/4 则(xx+yy-zz+2xy)/(xx-yy+zz-2xz) 得多少?(xx+yy-zz+2xy)/(xx-yy+zz-2xz)=[(x+y)^2-z^2]/[(x-z)^2-y^2]=(x+y+z)(x+y-z)/(x-z+y)(x-z-y)=(x+y+z)/(x-z-y)=(1/2+1/3+1/4)/(1/2-1/4-1/3)=-13还有...