# Exponential and logarithmic functions

Contents
Learn about logarithms, which are the inverses of exponents. Use logarithms to solve various equations. Then analyze both logarithmic and exponential functions and their graphs.

## Introduction to logarithms

Learn how we define logarithms and use this definition in order to evaluate various logarithms. For example, evaluate log_2(8) as 3 by realizing that 2^3=8.

## The constant e and the natural logarithm

Learn about a very special constant in math that has a pivotal role in the world of exponential and logarithmic function, the constant e.

## Properties of logarithms

Learn about special properties of logarithms that help us rewrite logarithmic expressions in different equivalent (much like we use properties of exponents to rewrite exponential expressions!).

## The change of base formula for logarithms

Learn how to rewrite any logarithmic expression in a different base. For example, rewrite log_2(3) as ln(3)/ln(2). This is very helpful for evaluating logarithms with a calculator, which only evaluates base-10 and base-e logarithms.

## Solving exponential equations with logarithms

Learn how to solve any exponential equation by using logarithms. For example, solve 2^x=3 by calculating log_2(3).

## Solving exponential models

Learn how to solve word problems that require exponential equations.

## Graphs of exponential functions

Learn about the graphs of advanced exponential functions of the form y=a*b^(x+c)+d.

## Graphs of logarithmic functions

Learn about the graphs of logarithmic functions, and how they relate to graphs of exponential functions.

## Logarithmic scale (optional)

Enrich your knowledge with some videos about logarithmic scales and how useful they are.