=sin50*(根号3*sin10+cos10)/cos10
=sin50/cos10*2*(cos30sin10+cos10sin30)
=sin50/cos10*2*sin40
=2*sin50*cos50/cos10
=sin100/cos10
=cos10/cos10
=1
=sin50*(根号3*sin10+cos10)/cos10
=sin50/cos10*2*(cos30sin10+cos10sin30)
=sin50/cos10*2*sin40
=2*sin50*cos50/cos10
=sin100/cos10
=cos10/cos10
=1