一道九年级上册二次根式数学题,见下图
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/06/17 23:34:18
一道九年级上册二次根式数学题,见下图
如图
![](http://img.wesiedu.com/upload/d/c9/dc9a0da85a41cdd136d32bafb36625ac.jpg)
如图
![](http://img.wesiedu.com/upload/d/c9/dc9a0da85a41cdd136d32bafb36625ac.jpg)
![一道九年级上册二次根式数学题,见下图](/uploads/image/z/7092950-14-0.jpg?t=%E4%B8%80%E9%81%93%E4%B9%9D%E5%B9%B4%E7%BA%A7%E4%B8%8A%E5%86%8C%E4%BA%8C%E6%AC%A1%E6%A0%B9%E5%BC%8F%E6%95%B0%E5%AD%A6%E9%A2%98%2C%E8%A7%81%E4%B8%8B%E5%9B%BE)
a=1/(√2-1)=(√2+1)/(√2-1)(√2+1)=√2+1
b=1/(√2+1)=(√2-1)/(√2+1)(√2-1)=√2-1
∴√(a²+b²+10)
=√[(√2+1)²+(√2-1)²+10]
=√(2+2√2+1+2-2√2+1+10)
=√16
=4
b=1/(√2+1)=(√2-1)/(√2+1)(√2-1)=√2-1
∴√(a²+b²+10)
=√[(√2+1)²+(√2-1)²+10]
=√(2+2√2+1+2-2√2+1+10)
=√16
=4