(tan10°-根号3)*(sin80°/cos40°

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(tan10°-根号3)*(sin80°/cos40°

(tan10°-根号3)*(sin80°/cos40°
(tan10°-根号3)*(sin80°/cos40°

(tan10°-根号3)*(sin80°/cos40°
(tan10°-√3)*(sin80°/cos40°)
=(tan10°-√3)*(sin80°/cos40°)
=(sin80/cos40)(cot80-√3)
=(sin80/cos40)*(cos80/sin80)-(sin80/cos40)*√3
=cos80/cos40-√3sin80/cos40
=-(√3sin80-cos80)/cos40
=-2(√3/2*sin80-1/2*cos80)/cos40
=-2(sin80cos30-cos80sin30)/cos40
=-2sin(80-30)/cos40
=-2sin50/cos40
=-2sin(90-40)/cos40
=-2cos40/cos40
=-2