# Logarithms: Introduction to "The Relationship"

Purplemath offers a complete lessonon the topic you have selected.Try the lesson below! This lesson is not yet availablein MathHelp.com. Logarithms: Introduction to "The Relationship" (page 1 of 3) Sections: Introduction to logs, Simplifying log expressions, Common and natural logs Logarithms are the "opposite" of exponentials, just as subtraction is the opposite of addition and division is the opposite of multiplication. Logs "undo" exponentials. In practical terms, I have found it useful to think of logs in terms of The Relationship: On the left-hand side above is the exponential statement "y = bx". If you can remember this relationship (that whatever had been the argument of the log becomes the "equals" and whatever had been the "equals" becomes the exponent in the exponential, and vice versa), then you shouldn't have too much trouble with logarithms. (I coined the term "The Relationship" myself. Convert "63 = 216" to the equivalent logarithmic expression.
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from Wolfram MathWorld
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