高中数学化简题sin50°(1+根号3)=

1个回答

  • 是这二个吗?

    sin50°(1+√3×cot80°)

    =sin50[sin80+√3×cos80]/sin80

    =2sin50{(1/2)cos80+(√3/2)sin80}/sin80

    =2sin50cos50/sin80

    =sin100/sin80

    =sin80/sin80

    =1

    sin50°[1+(√3)×tan10°]

    =sin50×[(√3)sin10+cos10]/cos10

    =(sin50/cos10)×2×(cos30sin10+cos10sin30)

    =(sin50/cos10)×2×sin40

    =2×sin50×cos50/cos10

    =sin100/cos10

    =cos10/cos10

    =1