There are two roots because of the

For a positive radicand, an equation such as x² = a has two real roots: x = √a and x = −√a. The positive and negative signs give two values whose squares equal the radicand, so the correct choice is “need to identify + and − roots of the radicand.” A negative radicand does not give two real roots, and a nonperfect square does not by itself explain why there are two roots.

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