Evaluate the surd expression: Compute (√13)^4 (write your answer as an integer).
Aptitude
Surds and Indices
Difficulty: Easy
Choose an option
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A520
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B169
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C28561
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D14280
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E13
Answer
Correct Answer: 169
Explanation
Introduction / Context:This is a straightforward surds-and-indices computation. Recognize how exponents distribute over radicals and simplify to an integer using exponent rules. No approximation is required.
Given Data / Assumptions:
- Expression: (√13)^4.
- Use index and radical rules: √13 = 13^(1/2).
Concept / Approach:Convert the radical to an exponent, then multiply exponents: (a^(m))^(n) = a^(m n). This yields a power of 13 that is easy to evaluate exactly.
Step-by-Step Solution:
(√13)^4 = (13^(1/2))^4 = 13^(1/2 * 4) = 13^2.13^2 = 169.Verification / Alternative check:Square first, then square again: (√13)^2 = 13; 13^2 = 169. Same result.
Why Other Options Are Wrong:
- 520, 14280: Products unrelated to the correct exponent evaluation.
- 28561: That is 13^4; we have 13^2.
- 13: That equals (√13)^2, not to the 4th power.
Common Pitfalls:Forgetting that exponents multiply when raising a power to a power, or misreading the expression as √(13^4).
Final Answer:169