1. 7.2 even answers 24)0.135326) 12.1825 28)$2330.6530) $1819.76 32) Between 10 and 11 years 34) About 0.85 mg 40a) 40b) 40c)

2. 7.3 Logarithmic Functions as Inverses P451

3. An exponential function is one-to-one. All one-to-one functions have inverses that are functions. So the exponential function has an inverse That is also a function. It is called the logarithmic function,

4. Logarithms: if and only if Read log base b of y

5. Common logarithms have base 10. They are written without showing the base 10. For example, is written

6. Use the definition to write Exponential Equations in Logarithmic form and visa versa. ex) What is the log form of each equation?

7. ex) What is the exponential form of each equation?

8. Evaluate the logarithm by finding common bases. ex) What is the value of

9. The magnitude of an earthquake is measured on a logarithmic scale called the Richter Scale. You can compare the intensity of two earthquakes using the formula where I is the intensity and M is the Magnitude.

10. Ex) In 1995, an earthquake in Mexico registered 8.0 on the Richter scale. In 2001, an earthquake in Washington state measured 6.8. How many times more intense was the 1995 earthquake than the 2001 earthquake?

11. The pH of a substance is equal to where is the concentration of hydrogen ions. The pH ranges from 0-14. The concentration of hydrogen ions is usually described in scientific notation. Ex) Find the concentration of hydrogen ions if the pH is 7.2

12. P456: 13-31odd, 32-35all, 47-53odd, 61-67odd, 73-75