lim [√(4x^2-x+2)-2x] = lim [√(4x^2-x+2)-2x][√(4x^2-x+2)+2x]/[√(4x^2-x+2)-2x]x->+∞ x->+∞= lim [(4x^2-x+2-4x^2]/[√(4x^2-x+2)+2x]x->+∞ = lim (-x+2)/[√(4x^2-x+2)+2x] x->+∞