Вычислите:

2x²-x-1=2(x+1/2)(x-1)=(2x+1)(x-1)
D=1+8=9
x1=(1-3)/4=-1/2
x2=(1+30/4=1
x³+2x²-x-2=x²(x+2)-(x+2)=(x+2)(x²-1)=(x+2)(x-1)(x+1)
(2x²-x-1)/(x³+2x²-x-2)=(2x+1)(x-1)/(x+2)(x-1)(x+1)=(2x+1)/(x+2)(x+1)
lim(2x+1)/(x+2)(x+1)=(2+1)/(1+2)(x+1)=3/3*2=1/2