Exam 9: Exponential and Logarithmic Functions

Calculate how many times more intense an earthquake with a Richter number of 8.1 is than an earthquake with a Richter number of 6.9. Please round the answer to the whole number.

Assume that , and . Use these values and the properties of logarithms to find the value. Do not use a calculator.

Use the properties of logarithms to write as a sum, difference, or product of logarithms. Assume x and z are positive numbers.

Which of these graphs could represent the graph of ?

The radioactive material Iodine-131 decays according to the formula , where t is expressed in days. To the nearest hundredth, how much Iodine-131 will be left if a sample of 325 grams decays for 15 days?

Which of the following could represent the graph of y = 0.5ln x + 1?

Graph the exponential function.

Assuming a Malthusian growth model and annual growth rate of 1.9%, by what factor will the current population of the earth increase in 45 years?

Suppose that Nora invested $900 at 9.25% compounded annually for 9 years and Patti invested $900 at 9% compounded quarterly for 9 years. At the end of 9 years, who will have the most money and by how much (to the nearest dollar)?

Solve the logarithmic equation. Check the solution.

Write the logarithmic expression as one logarithm. Assume that u , i , and p are positive numbers.

Graph the function . Remember that the graph of is given.