Answer:
sec²-2scθ+tanθ+tan²θ=1-sinθ/1+sinθ
sec²-2scθ+tanθ+tan²θ
= 1+sin²θ-2sinθ/cos²θ
=-1+sinθ/1+sinθ
=1-sinθ/sinθ+1
1-sinθ/sinθ+1=-1+sinθ/1+sinθ True
