(1)sin40度(ta n10度-根号下3) (2)tan70度cos10度(根号下3*tan20度-1) 这俩咋化简
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(1)sin40度(ta n10度-根号下3) (2)tan70度cos10度(根号下3*tan20度-1) 这俩咋化简啊?
![(1)sin40度(ta n10度-根号下3) (2)tan70度cos10度(根号下3*tan20度-1) 这俩咋化简](/uploads/image/z/5624025-33-5.jpg?t=%EF%BC%881%EF%BC%89sin40%E5%BA%A6%28ta+n10%E5%BA%A6-%E6%A0%B9%E5%8F%B7%E4%B8%8B3%29+%EF%BC%882%EF%BC%89tan70%E5%BA%A6cos10%E5%BA%A6%EF%BC%88%E6%A0%B9%E5%8F%B7%E4%B8%8B3%2Atan20%E5%BA%A6-1%EF%BC%89+%E8%BF%99%E4%BF%A9%E5%92%8B%E5%8C%96%E7%AE%80)
(1) sin40(sin10/cos10 - sin60/Cos60)
=Sin40/(Cos10Cos60) (Sin 10 Cos60 - Cos10Sin60)
=Sin40 Sin (-50)/ (Cos10 Cos60)
=-Sin40 Cos40 / (Sin80 Cos 60)
= - Sin80/ 2 /(Sin80 Cos 60)
= - 1/(2Cos60)
=-1
(2)Sin70/Cos70 Cos10 * (Sin 60/Cos60 Sin20 /Cos20 -1)
= Cos20 Cos 10/Cos70 *(Sin60 Sin20 - Cos60 Cos20)/ (Cos60 Cos20)
= Cos10 /Cos70 * (-Cos40) / Cos60
= - Cos 10 Cos40 /(Cos70 Cos60)
= - 2 Sin80 Cos40/ Sin 20
= - 8 sin20 Cos 20 Cos40 /Sin20
= -8 Cos20 Cos40
=-4 (Cos 20 - Cos (60)]
= -4 Cos 20 +2
=Sin40/(Cos10Cos60) (Sin 10 Cos60 - Cos10Sin60)
=Sin40 Sin (-50)/ (Cos10 Cos60)
=-Sin40 Cos40 / (Sin80 Cos 60)
= - Sin80/ 2 /(Sin80 Cos 60)
= - 1/(2Cos60)
=-1
(2)Sin70/Cos70 Cos10 * (Sin 60/Cos60 Sin20 /Cos20 -1)
= Cos20 Cos 10/Cos70 *(Sin60 Sin20 - Cos60 Cos20)/ (Cos60 Cos20)
= Cos10 /Cos70 * (-Cos40) / Cos60
= - Cos 10 Cos40 /(Cos70 Cos60)
= - 2 Sin80 Cos40/ Sin 20
= - 8 sin20 Cos 20 Cos40 /Sin20
= -8 Cos20 Cos40
=-4 (Cos 20 - Cos (60)]
= -4 Cos 20 +2
(1)sin40度(ta n10度-根号下3) (2)tan70度cos10度(根号下3*tan20度-1) 这俩咋化简
求值:tan70度*cos10度*(根号3tan20度-1)
tan70°cos10°(根号下3tan20°-1)
利用三角公式,化简tan70度cos10度(根号3tan20度-1)
化简:1、tan70°cos10°(根号3tan20°-1)
计算:tan70°cos10°(根号3·tan20°-1)
tan70°cos10°【根号3tan20°—1】
化简:(1).1/sin10°-根号3/cos10° (2).sin40°(tan10°-根号3) (3).tan70°
tan70°•cos10°(3tan20°-1)等于( )
求值:tan70°cos10°×(√3tan20°-1)
tan70°*cos10°(1-√3*tan20)的值
cot20度cos10度+根号3倍sin10度tan70度-2cos40度=?