Example

Determining the Domain, Graph, and Range of the Radical Function f(x)=x+2f(x) = \sqrt{x + 2}

For the radical function f(x)=x+2f(x) = \sqrt{x + 2}, the first step is to find the domain. Because the radical has an even index (22), the radicand must be greater than or equal to zero (x+20x + 2 \ge 0). Solving this indicates that x2x \ge -2, so the domain is [2,)[-2, \infty) in interval notation. To graph the function, select xx-values in this domain that produce perfect squares under the radical—such as 2-2, 1-1, 22, and 77—to easily evaluate the corresponding yy-values (00, 11, 22, and 33). By plotting these ordered pairs and connecting them, the graph visually confirms that the yy-values are strictly greater than or equal to zero. Consequently, the range of the function is [0,)[0, \infty).

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Updated 2026-05-26

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