求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的

来源：学生作业帮助网 编辑：作业帮 时间：2024/11/24 19:29:38
求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的
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求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的
求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11
求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11
=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的

求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的
cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11
=(cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11*2sinπ/11)/2sinπ/11
=(sin2π/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11)/2sinπ/11
=(1/2*sin4π/11*cos3π/11*cos4π/11*cos5π/11)/2sinπ/11
=(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11
=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11
=(1/8*sin6π/11*cos5π/11)/2sinπ/11
=(1/8*sin5π/11*cos5π/11)/2sinπ/11
=(1/16*sin10π/11)/2sinπ/11
=1/32
解题关键在于利用与构造sin2x=2SinxCosx.如果不明白,等你追问.

求值:cosπ/7*cos2π/7*cos3π/7 RT,求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11 cosπ/11×cos2π/11×cos3π/11×cos4π/11×cos5π/11=?求值cosπ/11×cos2π/11×cos3π/11×cos4π/11×cos5π/11=?求值 最后几步由sin6π/11×cos5π/11到sin10π/11怎样变得 求值：cosπ/17cos2π/17cos4π/17cos8π/17 求值cosπ/5cos2π/5cos4π/5cos8π/5 求值:cosπ/7·cos2π/7·cos4π/7 求值cos2π/5*tan5π 根号下1减sin(π+2)cos(π+2)化简是多少啊A sin2-cos2 B cos2-sin2 C +-(sin2-cos2) D sin2+cos2 求值:cosπ/7cos2π/7cos3π/7cos4π/7cos5π/7cos6π/7 求值:cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11) 求值：cos(π/11)-cos(2π/11)+cos(3π/11)-cos(4π/11)+cos(5π/11) 求COSπ/5*COS2π/5 cosπ/5×cos2π/5= COSπ/5乘以COS2π/5 cosπ/5×cos2π/5 cosπ/5cos2π/5 cosπ/5cos2π/5=? 求值：cos2π/7 * cos4π/7 * cos6π/7