Question

Doar punctele a și b

Answer 1

$\it a)\ m=2\Rightarrow f=X^3-2X^2-X+2\\ \\ f(2)=2^3-2\cdot2^2-2+2=8-8-2+2=0$

$\it b) X+1|f \Rightarrow f(-1)=0 \Rightarrow -1-2+1+m=0 \Rightarrow m=2 \Rightarrow \\ \\\Rightarrow f= X^3-2X^2-X+2=X^3+X^2-3X^2-3X+2X+2=\\ \\ =X^2(X+1)-3X(X+1)+2(X+1)=(X+1)(X^2-3X+2) \Rightarrow \\ \\ \Rightarrow f\ \vdots\ (X^2-3X+2)$