Question

Determinati numerele reale a si b daca $(x+1)ori(x-1)ori(x+2)ori(x-2)= x^{4}+a x^{2} +b$

Answer 1

(x+1) * (x-1) *(x+2)*(x-2) = x^4 +ax^2 +b
(x^2-1)*(x+2)*(x-2)=
(x^3+2x^2 -x-2)*(x-2)=
x^4-2x^3 +2x^3+4x^2+x^2-2x+2x+4=
x^4+5x^2+4 = x^4+ax^2+b => a=5 si b=4