若x1满足2x+2^x=5,x2满足2x+2log2(x+1)=5,求x1+x2=多少?2X+2^x=5x+2^(x-1)=2.52X+2log2(x-1)(2是底数)=5x+log2(x-1)=2.5其中y=2^(x-1)与y=log2(x-1)关于y=x-1对称y=2.5-x与前面指数对数曲线交点即为x1,x2.x1+x2为y=2.5-x,y=x-1交点
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![若x1满足2x+2^x=5,x2满足2x+2log2(x+1)=5,求x1+x2=多少?2X+2^x=5x+2^(x-1)=2.52X+2log2(x-1)(2是底数)=5x+log2(x-1)=2.5其中y=2^(x-1)与y=log2(x-1)关于y=x-1对称y=2.5-x与前面指数对数曲线交点即为x1,x2.x1+x2为y=2.5-x,y=x-1交点](/uploads/image/z/10255373-53-3.jpg?t=%E8%8B%A5x1%E6%BB%A1%E8%B6%B32x%2B2%5Ex%3D5%2Cx2%E6%BB%A1%E8%B6%B32x%2B2log2%28x%2B1%29%3D5%2C%E6%B1%82x1%2Bx2%3D%E5%A4%9A%E5%B0%91%3F2X%2B2%5Ex%3D5x%2B2%5E%28x-1%29%3D2.52X%2B2log2%28x-1%29%282%E6%98%AF%E5%BA%95%E6%95%B0%EF%BC%89%3D5x%2Blog2%28x-1%29%3D2.5%E5%85%B6%E4%B8%ADy%3D2%5E%28x-1%29%E4%B8%8Ey%3Dlog2%28x-1%29%E5%85%B3%E4%BA%8Ey%3Dx-1%E5%AF%B9%E7%A7%B0y%3D2.5-x%E4%B8%8E%E5%89%8D%E9%9D%A2%E6%8C%87%E6%95%B0%E5%AF%B9%E6%95%B0%E6%9B%B2%E7%BA%BF%E4%BA%A4%E7%82%B9%E5%8D%B3%E4%B8%BAx1%2Cx2.x1%2Bx2%E4%B8%BAy%3D2.5-x%2Cy%3Dx-1%E4%BA%A4%E7%82%B9)
若x1满足2x+2^x=5,x2满足2x+2log2(x+1)=5,求x1+x2=多少?2X+2^x=5x+2^(x-1)=2.52X+2log2(x-1)(2是底数)=5x+log2(x-1)=2.5其中y=2^(x-1)与y=log2(x-1)关于y=x-1对称y=2.5-x与前面指数对数曲线交点即为x1,x2.x1+x2为y=2.5-x,y=x-1交点
若x1满足2x+2^x=5,x2满足2x+2log2(x+1)=5,求x1+x2=多少?
2X+2^x=5
x+2^(x-1)=2.5
2X+2log2(x-1)(2是底数)=5
x+log2(x-1)=2.5
其中y=2^(x-1)与y=log2(x-1)关于y=x-1对称
y=2.5-x与前面指数
对数曲线交点即为x1,x2.
x1+x2为y=2.5-x,y=x-1交点横坐标2倍即3.5
对数曲线交点即为x1,x2.
x1+x2为y=2.5-x,y=x-1交点横坐标2倍即3.5
若x1满足2x+2^x=5,x2满足2x+2log2(x+1)=5,求x1+x2=多少?2X+2^x=5x+2^(x-1)=2.52X+2log2(x-1)(2是底数)=5x+log2(x-1)=2.5其中y=2^(x-1)与y=log2(x-1)关于y=x-1对称y=2.5-x与前面指数对数曲线交点即为x1,x2.x1+x2为y=2.5-x,y=x-1交点
第一个式子x+2^(x-1)=2.5,即2^(x-1)=2.5-x若令y=2^(x-1),则y=2.5-x,x1就是y=2^(x-1),y=2.5-x交点横坐标
同理x+log2(x-1)=2.5,log2(x-1)=2.5-x,若令y=log2(x-1),则y=2.5-x,x2就是y=log2(x-1),y=2.5-x交点横坐标
y=2^(x-1)与y=log2(x-1)关于y=x-1对称,y=2.5-x与y=x-1垂直,则y=2.5-x与前面指数、对数曲线交点x1,x2关于y=x-1对称,y=2.5-x,y=x-1交点就是x1,x2中点.这样你在画图看下就明白了