Thank you for your help, I actually worked it through and figured out those problems myself. However, there are still some confusions going on which I've been looking at for a good while.
Couple of other different problems.
cos θ = sin θ
cos θ - sin θ = 0
=> (cosθ - sin θ)ē = 0
=> cosēθ - 2cosθsinθ + sinēθ =0
=> 1-2cosθsinθ = 0
I'm pretty much stuck at this point. Did I do something wrong?
Another problem which I seem to have trouble with is:
(tan θ - 1)(sec θ - 1) = 0