请问各位大神，sin(π/8)=？有什么简便方法来算吗？ sinπ/8*cosπ/8
sin\u03c0/8=?cos(\u03c0/4)=1-2sin²(\u03c0/8)
2sin²(\u03c0/8)=1-cos(\u03c0/4)
sin(\u03c0/8)=\u221a{[1-cos(\u03c0/4)]/2}
=\u221a[(1-\u221a2/2)/2]
=\u221a[(2-\u221a2)/4]
=[\u221a(2-\u221a2)]/2
\u795d\u4f60\u5b66\u4e60\u8fdb\u6b65\uff0c\u6709\u4e0d\u61c2\u7684\u95ee\u9898\u53ef\u4ee5\u518d\u6765\u95ee\u6211(*\u2229_\u2229*)
详细步骤写在纸上了
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