Logarithmic online calculator - cardinality calculation

If the x-th power of a is equal to N (a>0, and a is not equal to 1), then the number X is called the logarithm of a base N, denoted as \(x=logaN\). Where a is called the base of the logarithm, N is called the true number, and x is called "the logarithm of N with a as the base".