黑哥16
幼苗
共回答了14个问题采纳率:92.9% 举报
sin(6°)cos(12°)cos(24°)cos(48°)
=sin6°·cos6°·cos12°·cos24°·cos48°/cos6°
=sin12°·cos12°·cos24°·cos48°/2cos6°
=sin24°·cos24°·cos48°/4cos6°
=sin48°·cos48°/8cos6°
=sin96°/16cos6°
=sin(180°-96°)/16cos6°
=sin84°/16cos6°
=1/16
1年前
7