Logarithms are another way of expressing powers. A logarithm is an index or power. When the bases are the same in index form, it can be easy to evaluate an index . The principles of indices make it possible to modify expressions containing powers more quickly than if they were written out whole. For x, logarithms can solve equations like 2x = 3. Since indices are used frequently in differential and integral calculus, proficiency in handling them is required in senior mathematics.