1.lim (sinx+cos2x)/(x+1)=0x→∞解题思路：有界/无穷大=02、lim [1-3/(4x)]^(2x)x→∞ lim {[1-3/(4x)]^(-4x/3)}^(-3/2)x→∞ =e^(-3/2)用到的公式：lim (1+ 1/x)^x=ex→∞
