x^2+x-3
=(x+1/2)²-13/4
=(x+1/2+√13/2)(x+1/2-√13/2) x^2+x-3=0
解得x=(-1±√13)/2
∴x^2+x-3=[x+(1+√13)/2][x+(1-√13)/2] x^2+x-3
=[x+(1+√13)/2][x+(1-√13)/2]
=(x+1/2+√13/2)(x+2-√13/2)
x^2+x-3=0
解得x=(-1±√13)/2
∴x^2+x-3=[x+(1+√13)/2][x+(1-√13)/2]
x^2+x-3
=(x+1/2)²-13/4
=(x+1/2+√13/2)(x+1/2-√13/2)