4x4-32x2+1
=4x4+12x3+2x2-12x3-36x2-6x+2x2+6x+1
=2x2.(2x2+6x+1)-6x.(2x2+6x+1)+(2x2+6x+1)
=(2x2+6x+1)(2x2- 6x+1)
= 4x4 - 4x2 + 1 - 28x2 = [(2x2)2 - 2.2x2 .1 + 12 ] - 28x2 = (2x2 - 1)2 - (\(\sqrt{28}\).x)2
= (2x2 - 1 - \(\sqrt{28}\)x) .(2x2 -1 + \(\sqrt{28}\)x) = (2x2 - 2\(\sqrt{7}\)x - 1). (2x2 + 2\(\sqrt{7}\)x -1)
Phân tích thành nhân tử:
8+12x+6x^2+x^3=
Bài làm :
Ta có :
4x4-32x2+1
=4x4+12x3+2x2-12x3-36x2-6x+2x2+6x+1
=2x2.(2x2+6x+1)-6x.(2x2+6x+1)+(2x2+6x+1)
=(2x2+6x+1)(2x2- 6x+1)
