3-[12] For the following, evaluate the limit if it exists. If it does not exist, explain why. If the limit is infinite, determine whether it is co or -co. x3 + 2x2 x - 1 (i) lim (ii) lim x--2x2+x- 2 x--2+ x2(x +2) x2 +7 -4 (iii) sin(x - 1) lim x2 - 3x (iv) lim X+3 x-1x2 + 2x -3