sinπ2

sinπ/2是什么意思即是sin90°sinπ/2=1

计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8)sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8)=sin(π/12)-cos（π/12)+2sin(π/8)cos(π/8)=

化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)=sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)=sinαcosβ+cosαsinβ+sinαcosβ-cosαsinβ+2sinα(-1*cos

sin(2π+a),sin(π+a),sin(5π+a)的区别为什么sin(2π+a)=sinasin(π+a)=-sina我习惯用一个圆表示建立一个二维坐标X轴代表sina值取以单位长度为直径画圆2π是360也就是一圈回到了原地sina不

sin^2(π/3-x)+sin^2(π/6+x)解sin²(π/3-x)+sin²(π/6+x)=sin²[π/2-(π/6+x)]+sin²(π/6+x)=cos²(π/6+x)+sin

化简:sin(-a)cos(2π+a)sin(-a-π)-sinacosasina=-sin^2acosa

1-2sin²π/8=sinπ/4由半角公式(1－cosα）/2=sin²(α/2)得1-2sin²(α/2)=cosα所以1-2sin²π/8=cosπ/4而cosπ/4=sinπ/4=√2/2那么

2sin(x+π/4)sin(x-π/4)=?2sin(x+π/4)sin(x-π/4)=2sin(x+π/4)sin[-π/2+(π/4+x)]=-2sin(x+π/4)cos(π/4+x)=-sin(2x+π/2)=-cos2x2sin

sin(-2π-a)是等于sin(-a)?完全正确是的

2sin(α+π/3）=sinα+______根号3乘以cosα

为什么sin(2π-α)=-sinα?sin(2π-α)=sin(π+π-α)=-sin(π-α)=-sinα.

Sin(π+π/6)Sin(2π+π/6)Sin(3π+π/6).Sin(2008π+π/6)求值（sinπ×cosπ/6+cosπ×sinπ/6）×（sin2π×cosπ/6+cos2π×sinπ/6）······（sin2008π×co

sin（2π-a)sin(π+a)cos(-π-a)/sin(3π-a)cos(π-a)sin(π/2+a)cos(π/2-a)/cos(π+a)+sin(π-a)cos(π/2+a)/sin(π+a)中间/是分母的意思,急用见到2π当0（

sin^2(π/4+x)sin^2(π/4+x)=[1-cos2(π/4+x)]/2=[1-cos(π/2+2x)]/2=1/2+sin2x/2运用公式Cos2A=CosA^2-SinA^2=1-2SinA^2sin^2(π/4+x)=[1

sin(πx/2)求导y=sin(πx/2)则y'=cos(πx/2)*(πx/2)'=π/2*cos(πx/2)

化简sin(2π+a)化简sin(2π+a)=sina终边相同角的同名三角函数值相等.sinasin(2π+a)=sina

已知tanx=3,则[sin(π+x)-2sin(π/2+x)]/[sin(7π-x)+sin(7π/2-x)]已知tanx=3,则[sin(π+x)-2sin(π/2+x)]/[sin(7π-x)+sin(7π/2-x)]的值是tanx=

2sinπ/6=sinπ/3,吗,求解释,还有-sinπ/6=sin-π/6吗这两个问题都可以用公式来求sin(2α)=2sinαcosαsin(-α)=-sinα第一个不是，第二个是

sin(n*π/2)*sin(n*π/3)*sin(n*π/4)*...*sin(n*π/n-1)求化简成一个关于n的表达式,真没有公式,只能说n是合数时其值为0,n是素数是非0,但没法看出规律n较大时数值非常接近0

比较大小(1)sin(-π/11)与sin(-π/17)(2)-sin(54π/7)与sin(-63π/8)(3)sin231°与cos260°sin(54π/7)=sin(54π/7-8π)=sin(-2π/7)sin(-63π/8)=s