請教兩題三角函數
1.
在\(\Delta ABC\)中,試求\(\displaystyle \frac{\sqrt{tan \frac{B}{2}tan \frac{C}{2}}}{cos \frac{A}{2}}+\frac{\sqrt{tan \frac{C}{2}tan \frac{A}{2}}}{cos \frac{B}{2}}+\frac{\sqrt{tan \frac{A}{2}tan \frac{B}{2}}}{cos \frac{C}{2}}\)的最大值為?
ANS:2
2.
\(P\)為\(\Delta ABC\)內部一點,且\(\angle PAB=\angle PBC=\angle PCA=15^{\circ}\),求\(\displaystyle \frac{1}{sin^2A}+\frac{1}{sin^2B}+\frac{1}{sin^2C}=\)?
ANS:\(8+4\sqrt{3}\)
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附件
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三角函數.zip
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2015-3-16 23:04, 下載次數: 4596