那位大哥帮帮忙~化简计算:cos23°cos83°+cos67°sin83°=_

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那位大哥帮帮忙~化简计算:cos23°cos83°+cos67°sin83°=_

根据sin(a+b)=sin(a)*cos(b)+cos(a)*sin(b)
cos23°cos83°+cos67°sin83°
=sin67°cos83°+cos67°sin83°
=sin(67+83)=sin150°
=sin(180°-30°)
=sin30°=1/2