Question

Phân tích đa thức thành nhân tử: \(x^4-2x^2-3\)

Answer 1

\(x^4-2x^2-3\\ < =>\left(x^2\right)^2-2x^2-3\\ < =>\left[\left(x^2\right)^2-2x^2+1\right]-4\\ < =>\left(x^2-1\right)^2-4\\ < =>\left(x^2-1\right)^2-2^2\\ < =>\left(x^2-1-2\right)\left(x^2-1+2\right)\\ < =>\left(x^2-3\right)\left(x^2+1\right)\)

Answer 2

\(A=x^4-2x^2-3=\left(x^2\right)^2-2x^2+1-4\)

\(=\left(x^2+1\right)^2-4=\left(x^2+1-4\right)\left(x^2+1+4\right)\)

\(=\left(x^2-3\right)\left(x^2+5\right)=\left(x-\sqrt{3}\right)\left(x+\sqrt{3}\right)\left(x^2+5\right)\)

Answer 3

Mình nghĩ là ntn