sin2a+2023π的和等于多少
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拓展:诱导公式哟那些:sin(-α) = -sinαcos(-α) = cosαtan (—a)=-tanαsin(π/2-α) = cosα cos(π/2-α) = sinαsin(π/2+α) = cosα cos(π/2+α) = -sinαsin(π-α) = sinαcos(π-α) = -cosαsin(π+α) = -sinα cos(π+α) = -cosα tanA= sinA/cosAtan(π/2+α)=-cotα tan(π/2-α)=cotα tan(π-α)=-tanα tan(π+α)=tanα诱导公式记背诀窍:奇变偶不变,符号看象限
咨询记录 · 回答于2023-01-09
sin2a+2023π的和等于多少
亲!很高兴为您解答,sin2a+2023π的和等于2sinacosa解析:sin(2a+2023π)=sin(2a+2023π+2π) (诱导公式)=sin(2a+2021π+2π)=sin2a=2sinacosa(二倍角公式)第一步减去整周期,第二步诱导,第三部正弦的二倍展开
好的谢谢
拓展:诱导公式哟那些:sin(-α) = -sinαcos(-α) = cosαtan (—a)=-tanαsin(π/2-α) = cosα cos(π/2-α) = sinαsin(π/2+α) = cosα cos(π/2+α) = -sinαsin(π-α) = sinαcos(π-α) = -cosαsin(π+α) = -sinα cos(π+α) = -cosα tanA= sinA/cosAtan(π/2+α)=-cotα tan(π/2-α)=cotα tan(π-α)=-tanα tan(π+α)=tanα诱导公式记背诀窍:奇变偶不变,符号看象限