Question

把下列各式因式分解：把下列各式因式分解：x^4+2x^3+3x^2+2x+1

Answer 1

x^4+2x^3+3x^2+2x+1
=x^4+2x^2+1+2x^3+x^2+2x
=(x^2+1)^2+x^3+x+x^3+x^2+x
=(x^2+1)^2+x(x^2+1)+x(x^2+x+1)
=(x^2+1)(x^2+x+1)+x(x^2+x+1)
=(x^2+1+x)(x^2+1+x)
=(x^2+1+x)^2