y=(x-1)/x2+2x+2值域

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y=(x-1)/x2+2x+2值域y=(x-1)/x2+2x+2值域y=(x-1)/x2+2x+2值域1/y=(x^2+2x+2)/(x-1)=[(x-1)^2+4(x-1)+5]/(x-1)=(x-

y=(x-1)/x2+2x+2值域
y=(x-1)/x2+2x+2值域

y=(x-1)/x2+2x+2值域
1/y=(x^2+2x+2)/(x-1)=[(x-1)^2+4(x-1)+5]/(x-1)=(x-1)+5/(x-1)+4
当x-1>0时
(x-1)+5/(x-1)>=2sqrt5
所以1/y>=2sqrt5+4
此时 0

y'=[5-(x-1)²]/[(x-1)²+1],当y’>0,1-√5<x<√5+1时,y=(x-1)/x2+2x+2为增函数;当y'<0,x<1-√5或x>√5+1时,y=(x-1)/x2+2x+2为减函数;y‘=0,函数有极值,x=1-√5时,y=(x-1)/x2+2x+2有最小值(2-√5)/2,,x=√5+1时,y=(x-1)/x2+2x+2有最大值(√5-2)/2;值...

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y'=[5-(x-1)²]/[(x-1)²+1],当y’>0,1-√5<x<√5+1时,y=(x-1)/x2+2x+2为增函数;当y'<0,x<1-√5或x>√5+1时,y=(x-1)/x2+2x+2为减函数;y‘=0,函数有极值,x=1-√5时,y=(x-1)/x2+2x+2有最小值(2-√5)/2,,x=√5+1时,y=(x-1)/x2+2x+2有最大值(√5-2)/2;值域[(2-√5)/2,(√5-2)/2]。

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