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[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=不要这种复制答案cos4
题目内容:
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=
不要这种复制答案
cos40°+sin50°×(1+√3tan10°)
=cos40°+sin50°×(tan60°-tan10°)/tan50°
=cos40°+(tan60°-tan10°)cos50°
=cos40°+√3cos50°-tan10°cos50°
=cos40°+√3sin40°-tan10°sin40°
=2[(1/2)cos40+(√3/2)sin40°]-(sin10°/cos10°)sin40°
=2(cos60°cos40°+sin60°sin40°)-[(sin10°)∧2/cos10°sin10°]sin40°
=2cos20°-[(1-cos20°)/sin20°]2sin20°cos20°
=2cos20°-2cos20°+2(cos20°) ∧2
=1+cos40°
sin70°√1+cos40°=sin70°(√2)cos20°=(√2)cos20°∧2
=√2/2(1+cos40°)
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=√2
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=
不要这种复制答案
cos40°+sin50°×(1+√3tan10°)
=cos40°+sin50°×(tan60°-tan10°)/tan50°
=cos40°+(tan60°-tan10°)cos50°
=cos40°+√3cos50°-tan10°cos50°
=cos40°+√3sin40°-tan10°sin40°
=2[(1/2)cos40+(√3/2)sin40°]-(sin10°/cos10°)sin40°
=2(cos60°cos40°+sin60°sin40°)-[(sin10°)∧2/cos10°sin10°]sin40°
=2cos20°-[(1-cos20°)/sin20°]2sin20°cos20°
=2cos20°-2cos20°+2(cos20°) ∧2
=1+cos40°
sin70°√1+cos40°=sin70°(√2)cos20°=(√2)cos20°∧2
=√2/2(1+cos40°)
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=√2
不要这种复制答案
cos40°+sin50°×(1+√3tan10°)
=cos40°+sin50°×(tan60°-tan10°)/tan50°
=cos40°+(tan60°-tan10°)cos50°
=cos40°+√3cos50°-tan10°cos50°
=cos40°+√3sin40°-tan10°sin40°
=2[(1/2)cos40+(√3/2)sin40°]-(sin10°/cos10°)sin40°
=2(cos60°cos40°+sin60°sin40°)-[(sin10°)∧2/cos10°sin10°]sin40°
=2cos20°-[(1-cos20°)/sin20°]2sin20°cos20°
=2cos20°-2cos20°+2(cos20°) ∧2
=1+cos40°
sin70°√1+cos40°=sin70°(√2)cos20°=(√2)cos20°∧2
=√2/2(1+cos40°)
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=√2
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