题目内容
化简[2sin500+sin100(1+
tan100)]
．
| 3 |
| 1+cos200 |
原式=[2sin50°+sin10°（1+
）]
=（2sin50°+sin10°•
）
=（2sin50°+2sin10°•
）
=
•
=2cos（40°-10°）•
=2cos30°×
=
．
| ||
| cos10° |
| 1+cos200 |
=（2sin50°+sin10°•
cos10°+
| ||
| cos10° |
| 1+cos200 |
=（2sin50°+2sin10°•
| sin(10°+30°) |
| cos10° |
| 1+cos200 |
=
| 2sin50°cos10°+2sin10°sin40° |
| cos10° |
| 1+cos200 |
=2cos（40°-10°）•
| ||
| cos10° |
=2cos30°×
| 2 |
=
| 6 |
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