化简：2sin^2（19/4π)+tan^2(37/4π)*cot(-9/4π)

化简：2sin^2（19/4π)+tan^2(37/4π)*cot(-9/4π) 若a属于(0,π/2)试比较tanα、tan(tanα)、tan(sinα) 化简cos(α-π)sin²(α+2π)/tan (α+4π)tan(α+π)cos³(-α-π) 化简:(sin(α-3π)*cos(-α))/(tan(α-5π)*cos^2(α-5π)*tan(4π-α)) 2sin ^2(19π/4）+tan^2（8π/3)*tan(-7π/4） 化简cos2(-α)-tan(2π+α)/sin(-α) cos²(-a)-sin(-a)/ tan(2π+a)化简 sin（-19π/6）=?已知[3Sin(π+a)+Cos(π-a)]/4Sin(-a)-Sin(5π/2+a)=2，求tan a tan(2π/13)+4sin(6π/13) 化简sin(9π+α）tan（3/2π+α）/cos(-4π-α）tan（15π+α）tan(7/2π-α） sin(2a+π/4）化简成tan 化简[sin(θ-5π)cot(π/2-θ)cos(8π-θ)]/[tan(3π-θ)tan(θ-3/2π)sin(-θ-4π)] sin(θ -5π)/tan(3π-θ)*cot(π/2-θ)/tan(θ -3/2π)*cos(8π-θ)/sin(-θ-4π)化简 化简cos(α -π )tan(α-2π)tan(2π-α)/sin(π+α) cos(π-α)tan(2π-α)tan(π-α)/sin(π+α) 化简 化简sin(3π-α)/[sin(-α-2π)]+cos(4π-α)/[cos(α-5π)]+tan(-α)/[tan(π+α)] Sinπ/3Tanπ/3+tanπ/6COSπ/6－Tanπ/4COSπ/2 化简sin(2π-α）tan（α+π）tan（-α-π）/