Verifying Trigometric Identitiis (Sin, Cos, Tan...) 20pts~

since cotθ=1 / tanθ
tanθ = sinθ/ cos θ
cotθ = cosθ/ sin θ
1-sin^2(θ) = cos^2(θ)
1.cosθ*cotθ = cos^2(θ)/ sinθ = (1-sin^2(θ))/sinθ
2. (sinθ/tanθ)+(cosθ/cotθ) = [sinθ/(sinθ/cosθ)]+[cosθ/(cosθ/sinθ) = sinθ+cosθ
3.(sinθ/(cosθ+1))+((cosθ-1)/sinθ) = sin^2(θ)+cos^2(θ)-1 = 1-1 = 0
4.(tan^2(θ)-cot^2(θ))/(tanθ+cotθ) = (tanθ+cotθ)*(tanθ-cotθ) / (tanθ+cotθ) = tanθ-cotθ
5.(cscθ-1)/cotθ = (1/sinθ-1)/(cosθ/sinθ)=
cotθ/(cscθ+1) = (cosθ/sinθ)/(1+sinθ/sinθ)
1-sin^2(θ) = cos^2(θ)
SO ,(cscθ-1)/cotθ = cotθ/(cscθ+1)