已知x>y>0,log3(x-y/2)^2=log3(xy),则log3(根号x/y-根号2)多少

问题描述:

已知x>y>0,log3(x-y/2)^2=log3(xy),则log3(根号x/y-根号2)多少

答:因为:x>y>0因为:log3 (x-y/2)^2 =log3(xy)所以:(x-y/2)^2=xy>0所以:x^2-xy+(y^2)/4=xy所以:x^2-2xy+(y^2) /4=0所以:(x-y)^2=(3/4)y^2解得:x-y=(√3/2)y(负值不符合舍弃)所以:x/y=(2+√3) /2所以:log3...