关于x的方程x²+4x+m=0的两根x1x2满足│x1-x2│=2求实数m的值请看看我这样做是哪里出错了应该怎么改x1+x2=-4 x1x2=m │x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2 2=16-4m m=7/2
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![关于x的方程x²+4x+m=0的两根x1x2满足│x1-x2│=2求实数m的值请看看我这样做是哪里出错了应该怎么改x1+x2=-4 x1x2=m │x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2 2=16-4m m=7/2](/uploads/image/z/999864-0-4.jpg?t=%E5%85%B3%E4%BA%8Ex%E7%9A%84%E6%96%B9%E7%A8%8Bx%26%23178%3B%2B4x%2Bm%3D0%E7%9A%84%E4%B8%A4%E6%A0%B9x1x2%E6%BB%A1%E8%B6%B3%E2%94%82x1-x2%E2%94%82%3D2%E6%B1%82%E5%AE%9E%E6%95%B0m%E7%9A%84%E5%80%BC%E8%AF%B7%E7%9C%8B%E7%9C%8B%E6%88%91%E8%BF%99%E6%A0%B7%E5%81%9A%E6%98%AF%E5%93%AA%E9%87%8C%E5%87%BA%E9%94%99%E4%BA%86%E5%BA%94%E8%AF%A5%E6%80%8E%E4%B9%88%E6%94%B9x1%2Bx2%3D-4+x1x2%3Dm+%E2%94%82x1-x2%E2%94%82%3D%E2%88%9A%28x1-x2%29%26%23178%3B%3D%28x1%2Bx2%29%26%23178%3B-4x1x2+2%3D16-4m+m%3D7%2F2)
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关于x的方程x²+4x+m=0的两根x1x2满足│x1-x2│=2求实数m的值请看看我这样做是哪里出错了应该怎么改x1+x2=-4 x1x2=m │x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2 2=16-4m m=7/2
关于x的方程x²+4x+m=0的两根x1x2满足│x1-x2│=2求实数m的值
请看看我这样做是哪里出错了应该怎么改x1+x2=-4 x1x2=m
│x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2
2=16-4m m=7/2
关于x的方程x²+4x+m=0的两根x1x2满足│x1-x2│=2求实数m的值请看看我这样做是哪里出错了应该怎么改x1+x2=-4 x1x2=m │x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2 2=16-4m m=7/2
│x1-x2│=√(x1-x2)²=(x1+x2)²-4x1x2
这里的最后一步你忘了加根号了
√((x1+x2)²-4x1x2)=2
16-4m = 4
m = 3
对f(x)=x^2+4x+m求导,得到f(x)‘=2x+4
若f(x)’=0,则x=-2
所以f(x)对称轴为x=-2
若两根差的绝对值等于2,则他们与x轴交点分别为(-1,0)(-3,0)
代入原解析式,得到1-4+m=0 所以m=3
m为3