
为什么sin15sin45sin30是错误的

unit circle单位圆常用三角函数表 unit circle之sin, cos, tan

sin²xcos²x1两边开根号是不是sinxcosx1

=√cos(x 45°) sinx-cosx =√(sinxcos45°-cosxsin45°) =√sin(x

如下图所示,图片来自@门酱胡安,图一为sin,cos函数图像,第二章为tan
为什么sin15sin45sin30是错误的
unit circle单位圆常用三角函数表 unit circle之sin, cos, tan
sin²xcos²x1两边开根号是不是sinxcosx1
=√cos(x 45°) sinx-cosx =√(sinxcos45°-cosxsin45°) =√sin(x
如下图所示,图片来自@门酱胡安,图一为sin,cos函数图像,第二章为tan