Question

Phân tích các đa thức sau thành nhân tử:

\(l,x^4+x^2+1\)

\(m,\left(x^2-8\right)^2+36\)

\(n,4x^4+81\)

Answer 1

\(x^4+x^2+1\)

\(=\left[\left(x^2\right)^2+2x^2.1+1^2\right]-x^2\)

\(=\left(x^2+1\right)^2-x^2\)

\(=\left(x^2+x+1\right)\left(x^2-x+1\right)\)

\(\left(x^2-8\right)^2+36\)

\(=x^4-16x^2+64+36\)

\(=\left[\left(x^2\right)^2-2.10x^2+10^2\right]-\left(2x\right)^2\)

\(=\left(x^2-10\right)^2-\left(2x\right)^2\)

\(=\left(x^2-10-2x\right)\left(x^2-10+2x\right)\)

\(4x^4+81\)

\(=\left[\left(2x^2\right)^2+2.2x^2.9+9^2\right]-\left(6x\right)^2\)

\(=\left(2x^2+9\right)-\left(6x\right)^2\)

\(=\left(2x^2+9-6x\right).\left(2x^2+9+6x\right)\)

Tham khảo nhé~

Answer 2

Noob quá cặc