When x→0+, the highest order of the following infinitesimals is x 2.

The so-called order refers to infinitesimal times. For example, when x→0+, the value of x 2 will become very small, and the value of x 3 will become smaller, so the order of x 3 is higher than x 2. So when x→0+, among the following infinitesimals, x 2 has the highest order.

Specifically, when x→0+, the following infinitesimal order is:

x^2:2

x^3:3

x^4:4

x^5:5

x^6:6

Therefore, when x→0+, among the following infinitesimals, the highest order is x 2.