2sin50°+2sin10°sin40°/cos10°

2sin50°+2sin10°sin40°/cos10° cos10°sin40°-sin10°sin50° sin10°sin40°+sin50°cos10° sin10°乘以sin40°+sin50°乘以sin80° sin10°乘以sin40°+sin50°乘以80° 2sin40°*sin50°等于什么 sin10°^2+cos40°^2+sin10°sin40° 2(sin40*sin50) 化简 sin40°（tan10°-√3)过程有些不明白原式=(tan10-tan60)sin40 =(sin10/cos10-sin60/cos60)sin40 =sin40(sin10cos60-cos10sin60)/(cos10cos60) =sin40*sin(10-60)/(sin80sin30)) =-sin40*sin50/(sin80sin30)) =-sin40cos40/(2sis40cos40sin30) =-1/(2 sin10°+sin20°+sin30°+sin40°+sin50°+……+sin2000°=? sin40°cos10°-SIN10°SIN50°的值是 2sin50°cos50°怎么等于cos50°cos40°+sin50°sin40° 化简:2sin50°+sin10°/cos10° 化简(2sin50°+sin10°)/cos10° （2sin10°+sin50°）÷cos50° sin10°sin50°为什么等于1/2(cos40-cos60) sin40°*(1-sin10°)/[sin10°*(cos20°)^2]2*根号3 化简 (sin40+2cos70)/sin50