求chegg这题答案！

小小小庆子

1. Approximately f(x) = 1 when x is large. So, it will diverge.

2. Assume z is very large, then function is approximately f(x) = e^(-x) is converging.

3. Assuming x is large, f(x) = 1/(x^3 + 2x^2) which is converging.

4. Assuming x is large, f(x) = 1/(x+3), which is diverging

不用谢！