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计算下列几个式子，①tan25°+tan35°+3tan25°tan35°，②1+tan15°1?tan15°，③2（sin35°cos25°+sin计算下列几个式子，①tan25°+tan35°+3tan25°tan35°，②1+tan15°1?tan15°，③2（sin35°cos25°+sin55°cos65°）．结果
题目详情
计算下列几个式子，①tan25°+tan35°+3tan25°tan35°，②1+tan15°1?tan15°，③2（sin35°cos25°+sin
计算下列几个式子，①tan25°+tan35°+
tan25°tan35°，②
，③2（sin35°cos25°+sin55°cos65°）．结果为
的是（ ）
A．①②
B．①③
C．①②③
D．②③
tan25°tan35°，②
，③2（sin35°cos25°+sin55°cos65°）．结果为
的是（ ）
A．①②
B．①③
C．①②③
D．②③
3 3
，③2（sin35°cos25°+sin55°cos65°）．结果为
的是（ ）
A．①②
B．①③
C．①②③
D．②③
1+tan15° 1+tan15° 1?tan15° 1?tan15°
的是（ ）
A．①②
B．①③
C．①②③
D．②③
3 3
计算下列几个式子，①tan25°+tan35°+
| 3 |
| 1+tan15° |
| 1?tan15° |
| 3 |
A．①②
B．①③
C．①②③
D．②③
| 3 |
| 1+tan15° |
| 1?tan15° |
| 3 |
A．①②
B．①③
C．①②③
D．②③
| 3 |
| 1+tan15° |
| 1?tan15° |
| 3 |
A．①②
B．①③
C．①②③
D．②③
| 1+tan15° |
| 1?tan15° |
| 3 |
A．①②
B．①③
C．①②③
D．②③
| 3 |
▼优质解答
答案和解析
①tan25°+tan35°+
tan25°tan35°=tan（25°+35°）（1-tan25°tan35°）+
tan25°tan35°
=
（1-tan25°tan35°）+
tan25°tan35°=
．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3tan25°tan35°=tan（25°+35°）（1-tan25°tan35°）+
tan25°tan35°
=
（1-tan25°tan35°）+
tan25°tan35°=
．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3tan25°tan35°
=
（1-tan25°tan35°）+
tan25°tan35°=
．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3（1-tan25°tan35°）+
tan25°tan35°=
．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3tan25°tan35°=
．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3．
②
=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
1+tan15° 1+tan15° 1+tan15°1?tan15° 1?tan15° 1?tan15°=
=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
1+
1+
1+
sin15° sin15° sin15°cos15° cos15° cos15°1?
1?
1?
sin15° sin15° sin15°cos15° cos15° cos15°=
=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
cos15°+sin15° cos15°+sin15° cos15°+sin15°cos15°?sin15° cos15°?sin15° cos15°?sin15°=
=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
sin(45°+15°)
sin(45°+15°)
2 2 2sin(45°+15°)
sin(45°?30°)
sin(45°?30°)
2 2 2sin(45°?30°)=
=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
sin60° sin60° sin60°sin30° sin30° sin30°=
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
故选：C．
3 3 3
故选：C．
| 3 |
| 3 |
=
| 3 |
| 3 |
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
| 3 |
=
| 3 |
| 3 |
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
=
| 3 |
| 3 |
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
| 3 |
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
②
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 1+tan15° |
| 1?tan15° |
1+
| ||
1?
|
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
1+
| ||
1?
|
| sin15° |
| cos15° |
| sin15° |
| cos15° |
| sin15° |
| cos15° |
| sin15° |
| cos15° |
| sin15° |
| cos15° |
| sin15° |
| cos15° |
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| cos15°+sin15° |
| cos15°?sin15° |
| ||
|
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| ||
|
| 2 |
| 2 |
| 2 |
| 2 |
| 2 |
| 2 |
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| sin60° |
| sin30° |
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
③2（sin35°cos25°+sin55°cos65°）=2（sin35°cos25°+cos35°sin25°）=2sin60°=
| 3 |
故选：C．
| 3 |
故选：C．
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