This all I got to help you..... cos half-angle formula: cos x/2=√[(1+cosx)/2] √[(1+cosx)/2]-sinx=0 √[(1+cosx)/2]=sinx square both sides (1+cosx)/2=sin^2x=1-cos^2x 1+cosx=2-2cos^2x
2cos^2x+cosx-1=0 (2cosx-1)(cosx+1)=0 .. 2cosx-1=0 cosx=1/2 x=π/3 and 5π/3 or cosx+1=0 cosx=-1 x=π HOPE I HELPED VANESSAN.. I HOPE ITS NOT THAT CONFUSING TOWARDS YOU :D
