计算：cosπ/15×cos2π/15×cos4π/15×cos8π/15
计算：cosπ/15×cos2π/15×cos4π/15×cos8π/15
数学人气：106 ℃时间：2020-05-20 17:50:10
优质解答
cosπ/15×cos2π/15×cos4π/15×cos8π/15=（sinπ/15×cosπ/15×cos2π/15×cos4π/15×cos8π/15）/（sinπ/15）=（1/2sin2π/15×cos2π/15×cos4π/15×cos8π/15）/（sinπ/15）=（1/4sin4π/15×cos4π/15...
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