<prompt> Sehemu ya grafu ya fx ax3 bx2 cx d imeonyeshwa. b ni nini?asyukubwa wa kitengo 1.5 cm;func halisi x halisi kurudi x 1x - 1x - 2;kuchoragrafufunc,-1.1,1.5;chora-1.5,0--1.5,0,Mishale6;chora0,-1--0,2.5,Mishale6;lebox, 1.5,0, E;lebofx, 0,2.5, N;nukta-1,0, -1,0, SE, fontsize10;nukta1,0, 1,0, SW, fontsize10;nukta0,2, 0,2, NE, fontsize10;asy  <response>: Tuna 0 f-1 -ab-cdna 0 f1 abcd,kwa hivyo bd0. Pia df0 2, hivyo b-2. 