Is this a function and what's the domain and range.

This is not a function. Why not? Because it fails the vertical line test. The input x = 3 leads to more than one output (eg: y = 1, y = 2, y = 3). A function is only possible if each input leads to exactly one output.

Domain = {3} so basically x is only allowed to be x = 3.

Range = set of y values such that y is between 1 and 5 (including both endpoints. As a compound inequality, the range is written as

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take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.