Khan Academy on a Stick
Logarithms
Log-a-what? No, this tutorial is about neither chopped wood nor music (actually logarithms do have applications in music), but it is fascinating nonetheless. You know how to take an exponent. Now you can think about what exponent you have to raise a number to to get another number. Yes, I agree--unstoppable fun for the whole family. No, seriously, logarithms are used everywhere (including to measure earthquakes and sound).
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Logarithms
Intro to logarithms. Learning that logarithms are just a way of expressing "the exponent that you have to raise a base to to get another number"
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Fancier logarithm expressions
Examples of logarithms that evaluate to fractional and negative values.
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Writing in logarithmic and exponential form
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Deducing with logarithmic and exponential form
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Solving exponential equation with logarithm
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Plotting points of logarithmic function
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Graphing logarithmic functions
Graphing Logarithmic Functions
Logarithm basics
If you understand how to take an exponent and you're looking to take your mathematical game to a new level, then you've found the right tutorial. Put simply and confusingly, logarithms are inverse operators to exponents (just as subtraction to addition or division to multiplication). As you'll see, taking a logarithm of something tells you what exponent you need to raise a base to to get that number.
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Introduction to logarithm properties
Introduction to the first two logarithm properties.
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Introduction to logarithm properties (part 2)
Second part of the introduction to logarithm properties.
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Logarithm of a power
Logarithm of a Power
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Sum of logarithms with same base
Sum of Logarithms with Same Base
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Using multiple logarithm properties to simplify
Using Multiple Logarithm Properties to Simplify
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Change of base formula
Change of Base Formula
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Proof: log a + log b = log ab
Proof of the logarithm property: log a + log b = log ab
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Proof: a log b = log(b^a), log a - log b = log(a/b)
Proofs of the logarithm properties: A(log B) = log (B^A) and log A - log B = log (A/B)
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Change of base formula proof
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Logarithmic equations
Logarithmic Equations
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Solving logarithmic equations
Solving Logarithmic Equations
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Solving logarithmic equations
Solving Logarithmic Equations
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Logarithmic scale
Understanding how logarithmic scale is different from linear scale and why it could be useful
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Richter scale
The basics of the logarithmic Richter and Moment Magnitude Scales to measure earthquakes
Logarithm properties
You want to go deeper in your understanding of logarithms. This tutorial does just that by exploring properties of logarithms that will help you manipulate them in entirely new ways (mostly falling out of exponent properties).
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Natural logarithm with a calculator
Natural Logarithm with a Calculator
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Calculator for natural logarithms
Calculator for Natural Logarithms
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Graphing natural logarithm function
Graphing Natural Logarithm Function
Natural logarithms
e is a special number that shows up throughout nature (you will appreciate this more and more as you develop your mathematical understanding). Given this, logarithms with base e have a special name--natural logarithms. In this tutorial, we will learn to evaluate and graph this special function.
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Logarithmic scale
Understanding how logarithmic scale is different from linear scale and why it could be useful
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Vi and Sal talk about the mysteries of Benford's law
Vi Hart visits Khan Academy and talks about Benford's Law with Sal
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Benford's law explanation (sequel to mysteries of Benford's law)
Vi and Sal talk through the intuition of Benford's law (part 2)
Logarithmic scale and patterns
Logarithms show up in science and music far more than you might first imagine. This tutorial explores where these appearances occur!