(cos^2 10°-cos^2 80°)+sin^2 20°
(cos^2 10°-cos^2 80°)+sin^2 20°
sin^2 80°等于 cos^2 10°?
2sin@+cos@等于?
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°
2cos³θ+sin²(360°-θ)+cos(360°-θ)-3/2+2cos²(180°-θ)+cos(-θ)怎样化
[2cos³θ+sin²(360°-θ)+cos(360°-θ)-3]/[2+2cos²(180°-θ)+cos(-θ)
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