求 根号3 tan10°+4sin10°的值
求 根号3 tan10°+4sin10°的值, 化简,根号3*tan10度+4sin10度, √3tan10°+4sin10°
√3tan10°+4sin10°
=2*(√3/2)tan10°+4sin10°
=2*sin60sin10°/cos10 +4sin10cos10/cos10
=2*(-1/2)(cos70-cos50)/cos10 + 2sin20/cos10
=(cos50-cos70)/cos10 + 2cos70/cos10
=(cos50-cos70+ 2cos70)/cos10
=(cos50+ cos70)/cos10
=(2cos60cos10)/cos10
=2cos60
=1
试求根号三*tan10度+4sin10度的值
原式=(根号三*sin10度+4sin10度cos10度)/cos10度
=(根号三*sin10度+2sin20度)/cos10度
=【根号三*sin10度+2sin(30度-10度)】/cos10度
=(根号三*sin10度+2sin30度cos10度-2cos30度sin10度)/cos10度
=(根号三*sin10度+cos10度-根号三sin10度)/cos10度
=cos10度/cos10度
=1
求根号3倍的tan10度-4sin10度
根号3倍的tan10度-4sin10度=
=1/cos(10°)[sqrt(3)/2 * 2sin(10°)-4sin(10°)cos(10°)]
=1/cos(10°)[sin(10°+30°)+sin(10°-30°)-2sin(20°)]=
=[2sin(20°)cos(20°)-3sin(20°)]/cos(10°)=
=sin(20°)/cos(10°) * (2cos(20°)-3)=
=4sin(10°)cos(20°)-6sin(10°)=
=2(sin(10°+20°)+sin(10°-20°))-6sin(10°)=
=1-8sin(10°)≈ -0.39
求值 根号3tan10 4sin10
数字后面有“°”吗?
字数10与4之间有无运算子?
请楼主及时补充。
√3tan10°+4sin10°
=√3(sin10°/cos10°)+4sin10°
=(√3sin10°+4sin10°cos10°)/cos10°
=(√3sin10°+4sin10°cos10°)/cos10°
=(2sin10°cos30°+2sin20°)/cos10°
=(sin40°-sin20°+2sin20°)/cos10°
=(sin40°+sin20°)/cos10°
=(2sin30°cos10°)/cos10°
=2sin30°
=2×1/2
=1。
求(根号3 tan10°+1)/(4cos^10°-2)sin10°的值
原(第一步把tan写成sin/cos形式)
=(根号3sin10+cos10)/(cos10(4cos10-2)sin
10)
=2*(cos30sin10+sin30cos10)/(2cos10sin10(4cos10-2)/2)
=2sin40/(2cos10-1)cos20
=2sin40/sin20cos20
=4
其中用到一些和差化积和二倍角公式
求sin4o度(tan10度-根号3)的值
原式=((sin10/cos10)-√3(cos10/cos10))*sin40
= 2(1/2*sin10-√3/2*cos10)/cos10 *sin40
=2 sin(10-60)/cos10 *sin40
=-2sin50*sin40/cos10
=-2cos40*sin40/cos10
=-sin80/cos10
=-1
[2sin50°+sin10°(1+根号3 tan10°)]根号(2sin^2 80°)的值
原式=[2sin50°+2sin10°*sin(10°+30°)/cos10°]*√2sin80°
=[2cos40°+2sin10°sin40°/cos10°]*√2cos10°
=2√2(cos40°cos10°+sin10°sin40°]
=2√2cos(40°-10°)
=√6
sin50°(1+根号3×tan10°)的值??
解: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