Question

化简（tan10度-根号3)乘sin50度分之cos10度（有过程的）

Answer 1

sin(a-b)=sinacosb-cosasinb
tan10=sin10/cos10
所以原式=(sin10/cos10-√3)xcos10/sin50
=(sin10-√3xcos10)/sin50
=2（1/2sin10-√3/2xcos10)/sin50 注将括号中的数字提取出来进行平方再开方刚好为2
=2（sin10xcos60-cos10xsin60)/sin50
=2sin(10-60)/son50
=2sin(-50)/sin50=-2sin50/sin50=--2

Answer 2

（tan10°-√3）×cos10°/sin50°
=（sin10°/cos10°-√3）×cos10°/sin50°
=（sin10°-√3cos10°）/sin50°
=2（1/2×sin10°-√3/2×cos10°）/sin50°
=2（cos60°sin10°-sin60°cos10°）/sin50°
=2×sin(10°-60°)/sin50°
=-2

Answer 3

sin(a-b)=sinacosb-cosasinb
tan10=sin10/cos10
原式=(sin10/cos10-√3)xcos10/sin50
=(sin10-√3xcos10)/sin50
=2（1/2sin10-√3/2xcos10)/sin50
=2（sin10xcos60-cos10xsin60)/sin50
=2sin(10-60)/son50
=2sin(-50)/sin50=-2sin50/sin50=-2