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sin(π/6-2x)=1/3q求sin(17π/6+2X)+sin^2(7π/3+2X)的值
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sin(π/6-2x)=1/3q求sin(17π/6+2X)+sin^2(7π/3+2X)的值
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sin(π/6-2x)=1/3,求sin(17π/6+2X)+sin²(7π/3+2X)的值
sin(17π/6+2x)+sin²(7π/3+2x)=sin(2π+5π/6+2x)+[sin(2π+π/3+2x)]²
=sin(5π/6+2x)+[sin(π/3+2x)]²=sin[π-(π/6-2x)]+[sin(π/3+2x)]²
=sin(π/6-2x)+{sin[π/2-(π/6-2x)]}²
=sin(π/6-2x)+cos²(π/6-2x)=sin(π/6-2x)+1-sin²(π/6-2x)=1/3+1-(1/3)²=11/9.
sin(17π/6+2x)+sin²(7π/3+2x)=sin(2π+5π/6+2x)+[sin(2π+π/3+2x)]²
=sin(5π/6+2x)+[sin(π/3+2x)]²=sin[π-(π/6-2x)]+[sin(π/3+2x)]²
=sin(π/6-2x)+{sin[π/2-(π/6-2x)]}²
=sin(π/6-2x)+cos²(π/6-2x)=sin(π/6-2x)+1-sin²(π/6-2x)=1/3+1-(1/3)²=11/9.
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