已知2lg((x-y)/2)=lg x+lg y,求log (3-2√2),(x/y)求log (3-2√2)^(x/y)
问题描述:
已知2lg((x-y)/2)=lg x+lg y,求log (3-2√2),(x/y)
求log (3-2√2)^(x/y)
答
....后面什么符号?log (3-2√2) “ ,” ? (x/y)
答
2lg((x-y)/2)=lg x+lg y有意义,则需x-y>0,x>0,y>0 x/y>1原式可化为:lg((x-y)/2)^2=lg(xy)∴(x-y)²/4=xy∴x²-2xy+y²=4xyx²-6xy+y²=0两边同时除以y²(x/y)²-6(x/y)+1=0 用求根...