Difficulty: Easy
Correct Answer: - 2
Explanation:
Introduction / Context:
We evaluate a logarithm with base less than 1 by expressing base and argument as powers of a common number (2) and then using exponent division.
Given Data / Assumptions:
Concept / Approach:
Use log_{a^m}(a^n) = n/m. For a base less than 1 (negative exponent on 2), the result may be negative even with a > 1 argument.
Step-by-Step Solution:
Verification / Alternative check:
Check: (0.125)^(−2) = (1/8)^(−2) = 8^2 = 64, confirming the result.
Why Other Options Are Wrong:
2 has the wrong sign for a base less than 1; 0 or “can’t be determined” contradict the exact exponent check above.
Common Pitfalls:
Ignoring that a fractional base (<1) leads to negative log values for arguments >1 is a common source of sign errors.
Final Answer:
- 2
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