Where does the mark scheme get these numbers from?

Q4B
Mark scheme
My working

NVM guys, i just realised that the quadratic formula was used! Sorry for anyone who may have wasted time

Your factorization, 3 lines from the bottom, is incorrect
The step from[Edit]
## Sin^2(\theta)+Sin(\theta)-1=0## , to
##Sin(\theta)[Sin(\theta)-1]=0##
Doesn't follow.
Distribute the terms in the bottom expression to test if they're equal.