懇請大大們救救小的四題!快掛點了!詳解更好 拜託了?

1
3Sinθ=Cosθ
Tanθ=Sinθ/Cosθ=1/3
Sec^2 θ=1+1/9=10/9
Secθ=√10/3>0
2
Tanθ=2/3
(Sinθ+2Cosθ)/(3Sinθ－Cosθ)
=(Sinθ/Cosθ+2Cosθ/Cosθ)/(3Sinθ/Cosθ－Cosθ/Cosθ)
=(Tanθ+2)/(3Tanθ－1)
=(3Tanθ+6)/(9Tanθ－3)
=(2+6)/(6－3)
=8/3
3(2Cosθ+1)/4=Cosθ
2Cosθ+1=4Cosθ
CosW=1/2
Sinθ=√3/2>0
4
Cotθ=-2
(5Sinθ+3Cosθ)/(2Sinθ－Cosθ)
=(5Sinθ/Sinθ+3Cosθ/Sinθ)/(2Sinθ/Sinθ－Cosθ/Sinθ)
=(5+3Cotθ)/(2－Cotθ)
=(5－6)/(2+2)
=－1/4