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cso15°cos30°+cos105°sin30°的值是()A.22B.32C.12D.1
题目详情
cso15°cos30°+cos105°sin30°的值是( )
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▼优质解答
答案和解析
cos15°cos30°+cos105°sin30°
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
.
故选A cos15°cos30°+cos105°sin30°
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
.
故选A cos15°cos30°+cos105°sin30°
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
.
故选A cos15°cos30°+cos105°sin30°
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
.
故选A
2
2 2 2 2 2 2 2 .
故选A
cos15°cos30°+cos105°sin30° =cos15°cos30°+cos(90°+15°)sin30° =cos15°cos30°-sin15°sin30° =cos45° =
故选A |
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
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2 |
故选A
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
| ||
2 |
故选A
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
| ||
2 |
故选A
=cos15°cos30°+cos(90°+15°)sin30°
=cos15°cos30°-sin15°sin30°
=cos45°
=
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故选A
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故选A
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