N
ngovanhuy203
31. cos2x+sin^2x+2cosx+1=0
(1-2sin^2x)+sin^2x+2cosx+1=0
(1-sin^2x)+2cosx+1=0
cos^2x+2cox+1=0
thanh PT bac 2 rui
ban giai tiep nha
(1-2sin^2x)+sin^2x+2cosx+1=0
(1-sin^2x)+2cosx+1=0
cos^2x+2cox+1=0
thanh PT bac 2 rui
ban giai tiep nha