(本小題12分)
已知函數(shù)

有兩個(gè)零點(diǎn);
(1)若函數(shù)的兩個(gè)零點(diǎn)是

和

,求k的值;
(2)若函數(shù)的兩個(gè)零點(diǎn)是

,求

的取值范圍.
(1)
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(2)

解:(1)


和

是函數(shù)

的兩個(gè)零點(diǎn),

,……………2分
則:

解的

; ………………4分
(2)若函數(shù)的兩個(gè)零點(diǎn)為


,

…………7分
則

…………9分

…… 12分
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
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
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
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
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
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
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
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
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
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
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
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
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(本小題滿分12分)
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
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
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