Which function returns the smallest integer that is greater than or equal to its argument?

The function that returns the smallest integer greater than or equal to its argument is the CEIL function. This function, short for "ceiling," effectively rounds a number up to the nearest whole number, regardless of its fractional component.

For example, using the CEIL function on the value 3.2 would yield 4, and applying it to -2.8 would return -2, which is the smallest integer that is still greater than -2.8. This characteristic makes the CEIL function particularly useful in various mathematical operations where rounding up is necessary.

In contrast, the ROUND function rounds to the nearest integer based on standard mathematical rules, which can round down if the fractional part is less than 0.5. The INT function truncates any decimal part, returning only the integer portion of a number, essentially rounding down to the nearest whole number. Lastly, the FLOOR function, oppositely, returns the largest integer that is less than or equal to its argument, rounding down rather than up.

Therefore, CEIL is specifically designed to meet the requirement of returning the smallest integer that is greater than or equal to the given argument, distinguishing it clearly from the other functions.