若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根,则k的取值范围是________(拜托=v=那啥还有一题= =已知x^2-5x+1=0,求x+1/x=________ x-1/x=_________
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![若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根,则k的取值范围是________(拜托=v=那啥还有一题= =已知x^2-5x+1=0,求x+1/x=________ x-1/x=_________](/uploads/image/z/11340983-47-3.jpg?t=%E8%8B%A5%E5%85%B3%E4%BA%8Ex%E7%9A%84%E6%96%B9%E7%A8%8B%28k-1%29x%5E2%2B2%28%E2%88%9Ak%2B1%29x%2B1%3D0%E6%9C%89%E4%B8%A4%E4%B8%AA%E4%B8%8D%E7%9B%B8%E7%AD%89%E7%9A%84%E5%AE%9E%E6%95%B0%E6%A0%B9%2C%E5%88%99k%E7%9A%84%E5%8F%96%E5%80%BC%E8%8C%83%E5%9B%B4%E6%98%AF________%EF%BC%88%E6%8B%9C%E6%89%98%3Dv%3D%E9%82%A3%E5%95%A5%E8%BF%98%E6%9C%89%E4%B8%80%E9%A2%98%3D+%3D%E5%B7%B2%E7%9F%A5x%5E2-5x%2B1%3D0%2C%E6%B1%82x%2B1%2Fx%3D________+++++++++++++++++++++++++++++x-1%2Fx%3D_________)
若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根,则k的取值范围是________(拜托=v=那啥还有一题= =已知x^2-5x+1=0,求x+1/x=________ x-1/x=_________
若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根,则k的取值范围是________
(拜托=v=
那啥还有一题= =
已知x^2-5x+1=0,求x+1/x=________
x-1/x=_________
若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根,则k的取值范围是________(拜托=v=那啥还有一题= =已知x^2-5x+1=0,求x+1/x=________ x-1/x=_________
有两个不相等的实数根,则
Δ=[2(√k+1)]²-4(k-1)>0
(√k+1)²-(k-1)>0
k+1-k+1>0
2>0恒成立
∴k∈R
△=b²-4ac
=[2(√k+1)]²-4(k-1)
=4(k+2√k+1)-4k+4
=4k+8√k+4-4k+4
=8√k+8
∵若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根
∴△>0
即8√k+8> 0
∵k≥0时√k≧0
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△=b²-4ac
=[2(√k+1)]²-4(k-1)
=4(k+2√k+1)-4k+4
=4k+8√k+4-4k+4
=8√k+8
∵若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根
∴△>0
即8√k+8> 0
∵k≥0时√k≧0
∴k≥0时, 8√k+8> 0
有∵若关于x的方程(k-1)x^2+2(√k+1)x+1=0有两个不相等的实数根
∴k-1≠0
∴k≠1
∴k的取值范围为 k≥0且k≠1
已知x^2-5x+1=0,求x+1/x=________
x-1/x=_________
∵x^2-5x+1=0
∴x²+1=5x
∴x+1/x=(x²+1)÷x
=5x÷x
=5
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