Logarithm
23 April 2023 (Updated 18 February 2026)
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What is a logarithm?
Logarithms are the inverse of exponentials. Asking what log₁₀ 100 is like asking “How many 10s do we need to multiply together to get 100?”. The answer is 2 because 10 x 10 is 100. So log₁₀10 = 2.
Here are some more examples:
- log₂8
- Question: How many 2s do we need to multiply to get 8?
- Answer: 3 (2 x 2 x 2 = 8)
- log₂16
- Question: How many 2s do we need to multiply to get 16?
- Answer: 4 (2 x 2 x 2 x 2 = 16)
- log₂32
- Question: How many 2s do we need to multiply to get 32?
- Answer: 5 (2 x 2 x 2 x 2 x 2= 32)