1) cos(2θ)+6sinēθ=4 and

2)cosθ=sinθ

1) cos(2θ)+6sinēθ=4

cos(2θ)-4=-6(1-cosēθ)

cos(2θ)-4=-6+cosēθ

-cosēθ+cos2θ=-2

-cosēθ+cos2θ+2=0

-cosēθ+2cosēθ+1=0

cosθ(-cosθ+2cosθ)+1=0

-cosθ+2cosθ+1=0

cosθ+1=0

cosθ=-1

and, as you can imagine, that's not the answer in the back of the book :P

2) cosθ=sinθ

cosθ=(1-cosēθ)

cosθ+cosēθ=1

and I'm stuck there.

Any help would be appreciated - I'm having considerable trouble with these (Headbang)