|
|||||||||
course syllabus assignments materials request a test proctor form |
1999 (Barnett, Ziegler, and Byleen) Chapter 5 Exponential and Logarithmic Functions 5.1 exponential functions 69. How does the graph of f(x) = 2x relate to the graph of g(x) = (1/2)x? (5)
70. What is the value of all exponential functions at x = 0? (3)
71. The population of Texas grows at the rate of 3% increase each year. If the population were 16,400,000 in 1985, then what would be the population in 2005? (5)
72. An investment grows exponentially in such a way that it doubles in 10 years. If $1000 is invested initially, then what is the amount after 7 years? (5)
5.2 the exponential function with base e 73. Simplify: (5)
74. Sketch the graph for: (5)
75. The spread of a certain epidemic is governed by ![]() where N(t) is the number that have been infected in the population, and t is measured in days.
5.3 logarithmic functions 76. How does the graph of f(x) = 2x relate to the graph of g(x) = log2 x? (5)
77. What is the value of all logarithmic functions at x = 1? (5)
78. If ex = 3, then what is the value of x? (5)
79. If ln x = -1, then what is the value of x? (5)
80. Simplify; that is, write as a single log function or simpler:
81. Compute the values of the following. Hint, you do not need a calculator.
5.4 common and natural logarithms 82. Compute the following values to 4 digits to the right of the decimal point:
83. Tritium, a radioactive isotope of hydrogen, has a half-life of 12.33 years. It is used, when mixed with a phosphorescence substance, to illuminate watch dials, rifle sights, etc. for night use. If 0.1 milligrams is used, how much remains after
84. It is determined that a wooden beam taken from the ruins of a house has 30.7% of the amount of C14 as a freshly cut log. The amount of C14 is in equilibrium when the entity is living. When it dies, the amount of C14 decays with a half-life of 5730 years. That is, where the amount at time t, A(t), is calculated from the initial amount, Ao, and the half-life, H. How long has it been since the wooden beam was harvested from its tree and incorporated into the structure of the house? (10)
85. The atmospheric pressure P, in pounds per square inch, decreases exponentially with altitude h, in miles (5280 ft/mi) above sea level, as given by
86. The sound level of a sound is measured in decibels which are defined according to: ![]() where Io = 10-16 watts per square centimeter.
87. The specification for an audio amplifier states that the signal-to-noise ratio is -50 db. This means the sound level of the noise in the system is 50db less than the sound level of the normal music. This difference in sound level corresponds to what ratio in sound intensities of the noise to the music? (5)
88. The magnitude of an earthquake, M, is generally measured on the Richter scale and is given as: ![]() where E0 = 104.40 joules. (Note, in class we defined M in terms of intensity not energy so the equation is somewhat different.)
89. The brightness of stars is expressed in terms of magnitudes on a numerical scale that increases as the brightness decreases; that is, a brighter star has a smaller magnitude. The magnitude m is given by: ![]() where L is the brightness of the star and Lo is the brightness of the dimmest stars visible to the naked eye.
|
||||||||
© 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Lawrence Turner |
|||||||||