高等数学limx→∞+ [√(X+1)(X+2)] -x

问题描述:

高等数学limx→∞+ [√(X+1)(X+2)] -x

原式=0

原式=limx→∞+ ((X+1)(X+2)-X^2)/([√(X+1)(X+2)] +x)
=limx→∞+(3X+2)/([√(X+1)(X+2)] +x)
=limx→∞+(3+2/x)/([√(1+1/x)(1+2/x)] +1)
=3/2