cos12/5派等于多少
cos12分之5π怎么算 -
sin(π/12)= √[(1-cos(π/6))/2]=√[(1-√3/2)/2]=√(2-√3)/2 =(√3-1)/(2√2)=√2(√3-1)/4 cos(5π/12)=sin(π/12) =√2(√3-1)/4 where 2-√3 = (1/2)(4-2√3) = (1/2)(√3-1)^2 √(2-√3) = (√3-1)/√2 到此结束了？。
cos12π/5=cos(2π+2π/5)=cos2π/5 cos11π/2=cos(6π-π/2)=cos（π/2)=cosπ/2=0
sin(π/12)= √[(1-cos(π/6))/2]=√[(1-√3/2)/2]=√(2-√3)/2 =(√3-1)/(2√2)=√2(√3-1)/4 cos(5π/12)=sin(π/12) =√2(√3-1)/4 where 2-√3 = (1/2)(4-2√3) = (1/2)(√3-1)^2 √(2-√3) = (√3-1)/√2 到此结束了？。
cos12π/5=cos(2π+2π/5)=cos2π/5 cos11π/2=cos(6π-π/2)=cos（π/2)=cosπ/2=0
=2*（cos（π/5））#178; -1 =（根号5-1）4 补充知识：cos（π/5）（根号5+1）4
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cos5分之12派怎么算 -
这是化简题吧cos5/12派=cos432º=cos72º
见下图：
cos5╱12派等于??用公式怎么算? -
【注：sin2x=2sinxcosx. sin(π-x)=sinx】解：原式=（1/2)×2sin(5π/12)cos(5π/12)=(1/2)sin(5π/6)=(1/2)sin[π-(π/6)]=(1/2)sin(π/6)=(1/2)×(1/2)=1/4.∴原式=1/4。
sin²π/12=(2-√3)/4 sin²π/12=4(2-√3)/16 sin²π/12=2(4-2√3)/16 sin²π/12=2(√3-1)²/16 sinπ/12=±√2*(√3-1)/4 因为sinπ/12>0 所以sinπ/12=√2*(√3-1)/4 sinπ/12=(√6-√2)/4 即cos5π/12=(√6-√2)/4 后面会介绍。
cos5∏/12 的值是多少 -
cos（5π/12）cos（π/4+π/6）cosπ/4cosπ/6-sinπ/4sinπ/6 =√2/2*√3/2-√2/2*1/2 =√6/4-√2/4 =（√6-√2）4
cos12兀它具有周期性，因为周期等于2所以cos12兀=cos2=0，所以结果等于0