Write the logarithmic form of 921/5 = 4.

2025

Write the logarithmic form of 921/5 = 4.

  1. A.

    log92(4)=1/5

  2. B.

    log1/5(4)=92

  3. C.

    log(1/5)=3

  4. D.

    None of these

Show answer & explanation

Correct answer: A

Concept:

For a > 0, a ≠ 1, and x > 0, the exponential form ab = x is equivalent to the logarithmic form loga(x) = b.

Application:

The given equation is 921/5 = 4.

  1. Compare 921/5 = 4 with the general form ab = x, giving a = 92, b = 1/5, and x = 4.

  2. Substitute these into loga(x) = b to get log92(4) = 1/5.

Cross-check:

Re-expanding log92(4) = 1/5 back into exponential form gives 921/5 = 4, exactly the given equation, confirming the two forms are consistent for these values.

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