I agree with the last three, couldn't do the Maclaurin though so I have no idea
Matrices almost ruined me as I initially tried A x A^k, but it worked once I used A^k x A
I think I got the vectors proof right, I ended up with something similar-looking to the required answer, multiplied top and bottom by 17 and got it.
For feasible values of y I got y< or equal to (7-root6)/2 and y> than or equal to (7+root6)/2
Can't remember any others