Exponential Growth and Decay
The exponential function is one of the most important and widely occurring functions in physics and biology. In biology, it may describe the growth of bacteria or animal populations, the decrease of the number of bacteria in response to a sterilization process, the growth of a tumor, or the absorption or excretion of a drug. (Exponential growth cannot continue forever because of limitations of nutrients, etc.) Knowledge of the exponential function makes it easier to understand birth and death rates, even when they are not constant. In physics, the exponential function describes the decay of radioactive nuclei, the emission of light by atoms, the absorption of light as it passes through matter, the change of voltage or current in some electrical circuits, the variation of temperature with time as a warm object cools, and the rate of some chemical reactions.
KeywordsDecay Rate Acute Lymphocytic Leukemia Exponential Growth Exponential Function Saving Account
Unable to display preview. Download preview PDF.
- Bartlett, A. (2004). The Essential Exponential! For the Future or Our Planet. Lincoln, NE, Center for Science, Mathematics & Computer Education.Google Scholar
- Haldane, J. B. S. (1985). On Being the Right Size and Other Essays. Oxford, Oxford University Press.Google Scholar
- Hemmingsen, A. M. (1960). Energy metabolism as related to body size and respiratory surfaces, and its evolution. Reports of the Steno Memorial Hospital and Nordinsk Insulin Laboratorium 9: 6–110.Google Scholar
- Kempe, C. H., H. K. Silver, and D. O'Brien (1970). Current Pediatric Diagnosis and Treatment, 2nd ed. Los Altos, CA, Lange.Google Scholar
- Murray, J. D. (2001). Mathematical Biology. New York, Springer-Verlag.Google Scholar
- Peters, R. H. (1983). The Ecological Implications of Body Size. Cambridge, Cambridge University Press.Google Scholar
- Riggs, D. S. (1970). The Mathematical Approach to Physiological Problems. Cambridge, MA, MIT Press.Google Scholar
- Schmidt-Nielsen, K. (1984). Scaling: Why is Animal Size so Important? Cambridge, Cambridge University Press.Google Scholar
- Zumoff, B., H. Hart, and L. Hellman (1966). Considerations of mortality in certain chronic diseases. Ann. Intern. Med. 64: 595–601.Google Scholar