问题
选择题
在锐角三角形ABC中,b=1,c=2,则实数a的取值范围是( )
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答案
∵锐角三角形ABC中,b=1,c=2,
若C为三角形ABC中的最大角,即a≤c
则a>
=c2-b2
,即3
<a≤23
若A为三角形ABC中的最大角,即a>c
则a<
=c2+b2
,即2<a<5 5
综上满足条件的实数a的取值范围是
<a<3 5
故选C
在锐角三角形ABC中,b=1,c=2,则实数a的取值范围是( )
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∵锐角三角形ABC中,b=1,c=2,
若C为三角形ABC中的最大角,即a≤c
则a>
=c2-b2
,即3
<a≤23
若A为三角形ABC中的最大角,即a>c
则a<
=c2+b2
,即2<a<5 5
综上满足条件的实数a的取值范围是
<a<3 5
故选C
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