cos(-3/5π),cos(14/5π),sin(2/5π)比较大小
θ∈(0,π/2),比较cosθ、sin(cosθ)、cos(sinθ)的大小
比较大小sin(cosα)与cos(sinα)(0<α<π/2)
α∈(0,π/2 ),比较 sin(cosα) 与cos(sinα)大小
怎么比较cos(3π /5),cos(π /4)的大小?是要根据图像吗?
若θ∈[0,(π/2)],试比较cos(sinθ)与sin(cosθ)的大小.
已知α属于(0,π/2),比较sin(cosα)与cos(sinα)的大小
不求值,分别比较下列各组中两个三角函数值的大小(1)sin(-π/7)和sin(-π/5)(2)cos
已知cos(π/2+a)=2sin(a-π/2)求sin(π-a)+cos(a+π)/5cos(5π/2-a)+3sin
【1】化简:sin(a-5π)/cos(3π-a)×cos(π/2-a)/sin(a-3π)×cos(8π-a)/sin
化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-
sin(π-θ)+cos(2π-θ)/cos(5π/2-θ)+sin(3π/2+θ)=2,则sinθcosθ=_____
已知 sin(θ+kπ)=-2cos (θ+kπ) 求 ⑴4sinθ-2cosθ/5cosθ+3sinθ; ⑵(1/4)