sin15°=(â6-â2)/4
cos15°=(â6+â2)/4
tan15°=2-â3
计ç®æ¥éª¤ï¼ä»¥sin15°为ä¾ï¼å¦ä¸ï¼
éï¼LATEX代ç
&\sin15^\circ=\sin(45^\circ-30^\circ)\\
=&\sin45^\circ \cos30^\circ-\cos45^\circ\sin30^\circ\\
=&\frac{\sqrt[]{2} }{2}\frac{\sqrt[]{3} }{2}-\frac{\sqrt[]{2} }{2}\frac{1 }{2}\\
=&\frac{\sqrt[]{6}-\sqrt[]{2} }{4}\\
\approx &0.2588