Có $A= 3sinx-4sin^3x+4sinxcosx+2-4sin^2x+2sinx+4cosx+3$$= 5sinx+5 -4sin^2-4sin^3+4sinxcosx+4cosx$$=5(sinx+1) -4sin^2(sinx+1)+4cosx(sinx+1)$$=(sinx+1)(5-4sin^2x+4cosx)$$=(sinx+1)(5-4+4cosx^2+4cosx)$$=(sinx+1)(cosx+2)^2$
Có $A= 3sinx-4sin^3x+4sinxcosx+2-4sin^2x+2sinx+4cosx+3$$= 5sinx+5 -4sin^2-4sin^3+4sinxcosx+4cosx$$=5(sinx+1) -4sin^2(sinx+1)+4cosx(sinx+1)$$=(sinx+1)(5-4sin^2x+4cosx)$
Có $A= 3sinx-4sin^3x+4sinxcosx+2-4sin^2x+2sinx+4cosx+3$$= 5sinx+5 -4sin^2-4sin^3+4sinxcosx+4cosx$$=5(sinx+1) -4sin^2(sinx+1)+4cosx(sinx+1)$$=(sinx+1)(5-4sin^2x+4cosx)$
$=(sinx+1)(5-4+4cosx^2+4cosx)$$=(sinx+1)(cosx+2)^2$