Final answer:
The expression that can be used to approximate the expression loga(x) is ln(x)/ln(a).
Step-by-step explanation:
The expression that can be used to approximate the expression loga(x) is ln(x)/ln(a).
The natural logarithm, ln(x), can be used to approximate any logarithm since it is a logarithm with base e, where e is approximately 2.7183. The denominator, ln(a), represents the logarithm of the base a.
For example, if we want to approximate log2(8), we can use ln(8)/ln(2) which is approximately 3 since ln(8) is approximately 2.0794 and ln(2) is approximately 0.6931.