[最新] √3/2 cos 514632-Cos x=2/3

(cos3 )=cos3( −3sin2( )cos( ) (cos3 )=4cos3( )−3cos( ) (tan3 )= 3(𝑥) 1−3tan2(𝑥) (cot3 )= 3(𝑥) 1−3cot2(𝑥) Function Ranges 2 ≤ ≤ 𝜋 2 2 < < 𝜋 2 csc( ) −∞< ≤1 ∪1≤