The function y=[x] is called integer function, also called Gaussian function. The largest integer that does not exceed the real number x is called the integer part of x, and is recorded as [x]. This function is widely used in number theory, function drawing and computer field.

brief introduction

Round up, regardless of rounding rules, as long as there is an integer before the decimal point, add 1. Round down, regardless of rounding rules, as long as there is a decimal after it, ignore the given decimal. For example: 4.9, call the rounded function and get 4. Call the rounding function and get 5.

The operation of rounding down is called the lower limit, which is expressed by mathematical symbols, and the operation of rounding up is called the upper limit, which is expressed by mathematical symbols.