化简:cosπ5
化简cos(π/12)*cos(5π/12)
化简:cos(-π-α)
化简sin(x)(cos(x)+cos(3x)+cos(5x)+cos(7x))
化简cos(π/12-α)-根号3cos(5π/12+α)
化简sin(3π-x)cos(x-3/2)cos(4π-x)/tan(x-5π)cos(π/2+x)sin(x-5/2π
【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-
若cos(5π12
已知cos(5π12
①化简[sin(2π+α)*cos(7π-α)]/cos(-α)②已知cosθ=-3/5,θ∈(π/2,π),求sin(
计算cos(a+5π/12)cos(a+π/6)+cos(π/12-a)cos(π/3-a)
化简cos平方α+cos平方(α-π/3)+cos平方(α+π/3) 急、~