Algebra II : Square Roots

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #21 : Square Roots

Evaluate:  \(\displaystyle \sqrt{0}-\sqrt1-\sqrt9-\sqrt{16}\)

Possible Answers:

\(\displaystyle \textup{Undefined.}\)

\(\displaystyle 7\)

\(\displaystyle -7\)

\(\displaystyle -3\)

\(\displaystyle -8\)

Correct answer:

\(\displaystyle -8\)

Explanation:

Evaluate each square root.  The square root of a number evaluates into a number which multiplies by itself to achieve the number in the square root.

\(\displaystyle \sqrt0 =0\)

\(\displaystyle \sqrt{1} = 1\)

\(\displaystyle \sqrt{9} =3\)

\(\displaystyle \sqrt{16}=4\)

Substitute the terms back into the expression.

\(\displaystyle \sqrt{0}-\sqrt1-\sqrt9-\sqrt{16} = 0-1-3-4 = -8\)

The answer is:  \(\displaystyle -8\)

Example Question #21 : Radicals

Solve:  \(\displaystyle \sqrt{16}+\sqrt{196}-\sqrt{36}\)

Possible Answers:

\(\displaystyle 18\)

\(\displaystyle -18\)

\(\displaystyle -12\)

\(\displaystyle 12\)

\(\displaystyle 16\)

Correct answer:

\(\displaystyle 12\)

Explanation:

Solve each radical.  The square root determines a number that multiples by itself to equal the number inside the square root.

\(\displaystyle \sqrt{16}=4\)

\(\displaystyle \sqrt{196}=14\)

\(\displaystyle \sqrt{36}=6\)

Rewrite the expression.

\(\displaystyle \sqrt{16}+\sqrt{196}-\sqrt{36} = 4+14-6\)

The answer is:  \(\displaystyle 12\)

Example Question #21 : Square Roots

True or false: \(\displaystyle \sqrt{52}\) is a radical expression in simplest form.

Possible Answers:

True

False

Correct answer:

False

Explanation:

A radical expression which is the \(\displaystyle n\)th root of a constant is in simplest form if and only if, when the radicand is expressed as the product of prime factors, no factor appears \(\displaystyle n\) or more times.  Since \(\displaystyle \sqrt{52}\) is a square, or second, root, find the prime factorization of 52, and determine whether any prime factor appears two or more times.

52 can be broken down as

\(\displaystyle 52 = 2 \times 26\)

and further as

\(\displaystyle 52 = 2 \times 2 \times 13\)

The factor 2 appears twice, so \(\displaystyle \sqrt{52}\) is not in simplest form.

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