cos^2 80°+sin^2 50°-sin190°cos320°
sin^2 80°等于 cos^2 10°?
(cos^2 10°-cos^2 80°)+sin^2 20°
Sin^2 45°+cos^2 45°=?
(cos^2)15°+(sin^2)15°等于多少
化简:根号1+2sin(40°)cos(40°)
(cos^2)15°-(sin^2)15等于多少
化简cos^2(-α)-[tan(360°+α)/sin(-α)]
sinΘ-2cosΘ=0,Θ属于(0.,90°),求sinΘ、cosΘ的值.
求2sin(-1110°)-sin960°+根号2cos(-225°)-cos(-210°)
2cos 30°-2sin 60°·cos 45°=?
计算[3/(sin^2)20°-[1/(cos^2)20°]+64(sin^2)20°
sin^2是什么,sin^260°等于什么,还有cos^43兀/2等于什么