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If log a equals zero, the value of a is
Ainfinity
Bzero
Cten
Dexactly one
Answer & Solution
Correct answer: D. exactly one
1. By log definition, log_b(x) = 0 implies b^0 = x.
2. For any positive base b, b^0 = 1.
3. So the value satisfying log a = 0 is exactly 1.
4. Zero (b), ten (c), and infinity (d) are not consistent with the rule.
_Source: ICAI BoS Foundation Paper 3, Ch 1 Unit IV 'Logarithms', p.17_
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