Missing Exponent Finder

Enter the base and result value to quickly find the missing exponent.

Calculate the Missing Exponent: x? = y

Result

How to Calculate a Missing Exponent

If the base and the result value are known, logarithms can be used to determine the missing exponent. Follow these steps:

  1. Identify the Base and Result Value: Let the base be \( a \) and the result value be \( V \).
  2. Apply the Logarithm Formula: Use the formula \( n = \log_a V \) Here, \( \log_a V \) represents the logarithm of \( V \) with base \( a \).
  3. Convert to Common Logarithms: Use the change of base formula to simplify the calculation: \( n = \frac{\log V}{\log a} \)

Examples

Example 1: Find the missing exponent for \( 2^n = 32 \)

Solution:

Given: Base \( a = 2 \), Result \( V = 32 \).

Calculation:

Using the formula: \( n = \log_2 32 \)

Convert to common logarithms:

\( n = \frac{\log 32}{\log 2} \)

Compute values:

\( \frac{\log 32}{\log 2} = \frac{1.505}{0.301} = 5 \)

Result: The missing exponent is 5, meaning \( 2^5 = 32 \).

Example 2: Find the missing exponent for \( 3^n = 81 \)

Solution:

Given: Base \( a = 3 \), Result \( V = 81 \).

Using the formula:

\( n = \log_3 81 \)

Convert to common logarithms:

\( n = \frac{\log 81}{\log 3} \)

Compute values:

\( \frac{\log 81}{\log 3} = \frac{1.908}{0.477} = 4 \)

Result: The missing exponent is 4, meaning \( 3^4 = 81 \).

Example 3: Find the missing exponent for \( 5^n = 125 \)

Solution:

Given: Base \( a = 5 \), Result \( V = 125 \).

Using the formula:

\( n = \log_5 125 \)

Convert to common logarithms:

\( n = \frac{\log 125}{\log 5} \)

Compute values:

\( \frac{\log 125}{\log 5} = \frac{2.096}{0.699} = 3 \)

Result: The missing exponent is 3, meaning \( 5^3 = 125 \).