急需数学题.1.21.已知xˆ2-4x+1=0,求xˆ2+1/xˆ2的值.2.已知xˆ2+yˆ2+2x-6y+10=0,求xˆy的值.3.已知x+y+z=0,且xy+yz+xz=0,求xˆ2+yˆ2+zˆ2的值.要有过程的。
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![急需数学题.1.21.已知xˆ2-4x+1=0,求xˆ2+1/xˆ2的值.2.已知xˆ2+yˆ2+2x-6y+10=0,求xˆy的值.3.已知x+y+z=0,且xy+yz+xz=0,求xˆ2+yˆ2+zˆ2的值.要有过程的。](/uploads/image/z/255560-32-0.jpg?t=%E6%80%A5%E9%9C%80%E6%95%B0%E5%AD%A6%E9%A2%98.1.21.%E5%B7%B2%E7%9F%A5x%26%23710%3B2-4x%2B1%3D0%2C%E6%B1%82x%26%23710%3B2%2B1%2Fx%26%23710%3B2%E7%9A%84%E5%80%BC.2.%E5%B7%B2%E7%9F%A5x%26%23710%3B2%2By%26%23710%3B2%2B2x-6y%2B10%3D0%2C%E6%B1%82x%26%23710%3By%E7%9A%84%E5%80%BC.3.%E5%B7%B2%E7%9F%A5x%2By%2Bz%3D0%2C%E4%B8%94xy%2Byz%2Bxz%3D0%2C%E6%B1%82x%26%23710%3B2%2By%26%23710%3B2%2Bz%26%23710%3B2%E7%9A%84%E5%80%BC.%E8%A6%81%E6%9C%89%E8%BF%87%E7%A8%8B%E7%9A%84%E3%80%82)
急需数学题.1.21.已知xˆ2-4x+1=0,求xˆ2+1/xˆ2的值.2.已知xˆ2+yˆ2+2x-6y+10=0,求xˆy的值.3.已知x+y+z=0,且xy+yz+xz=0,求xˆ2+yˆ2+zˆ2的值.要有过程的。
急需数学题.1.2
1.已知xˆ2-4x+1=0,求xˆ2+1/xˆ2的值.
2.已知xˆ2+yˆ2+2x-6y+10=0,求xˆy的值.
3.已知x+y+z=0,且xy+yz+xz=0,求xˆ2+yˆ2+zˆ2的值.
要有过程的。
急需数学题.1.21.已知xˆ2-4x+1=0,求xˆ2+1/xˆ2的值.2.已知xˆ2+yˆ2+2x-6y+10=0,求xˆy的值.3.已知x+y+z=0,且xy+yz+xz=0,求xˆ2+yˆ2+zˆ2的值.要有过程的。
1.xˆ2-4x+1=(x-2)²-3=0
x=2+√3或2-√3
所以xˆ2+1/xˆ2=8-4√3(当x=2+√3)或xˆ2+1/xˆ2=8+4√3(当x=2-√3)
2.xˆ2+yˆ2+2x-6y+10=(x+1)²+(y-3)²=0
x=-1 y=3代入xˆy得:xˆy=-1
3.(x+y+z)²=x²+y²+z²+2(xy+xz+yz)=0
又xy+yz+xz=0
所以x²+y²+z²=0
xy
没学过