1. Logarithms Logs ARE EXPONENTS!! Logarithms are a way to rewrite exponential equations. They help us solve equations as well.

2. We are going to start by taking the inverse of an exponential equation! When finding an inverse, you switch x & y and solve for y! At this point, we have no way to solve for y. So now we will rewrite this in logarithmic form. There are three things you need to recognize! The base, the exponent and the answer. BaseExponentAnswer

3. Generic Equation for logarithms: To evaluate a logarithm, think to yourself, if I take the base and raise it to the given exponent, what is my answer? To evaluate x, we need to think to ourselves, what is the base raised to the exponent, or for this example, what is 4 raised to the 2 nd power?

4. Remember: Logs ARE EXPONENTS! log = exponent Page 1

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7. Graphing y=log (x) The calculator can only graph base 10, which is what our entire mathematical system is, base 10. So we will look at that graph. When no base is indicated, we are in base 10 Notice that the log graph crosses the x-axis at the point (1,0) What is the domain and range?

8. Page 1 You can’t graph base 5, but base 10 is close, so use that graph to help you!

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10. Remember what the graph looks like. We CAN NOT take the log of a negative number or 0

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13. Page 2 Remember: Logs ARE EXPONENTS!!

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15. Homework Page 2 #13-16 TOP #2-14 even bottom