..I have to find all answers to these on the interval 0-2 pi, I think I'm getting them right but I'm not 100% positive

For the first one I had

and I did

Mr F says: Wrong. You have to factorise:

or .

and on the interval 0-2pi I got

Mr F says: For reasons given above, you're missing solutions.

the second one I have to do

and I got

Mr F advises: Use a different symbol to x. x is already being used in the question. Use w = sin x so that w^2 - 2w - 3 = 0.

and for the interval I got

are there any answers on the interval that I am missing? Mr F says: No.

[snip]