Advanced Algebra Unit 4: Exponential and Logarithms Excerpts from Georgia Department of Education Webinar October 3, 2013 melissa.stewart@hallco.org October 2013 Warm-Up Four physicists describe the amount of radioactive substance, in grams, left after years. Are the four equations equivalent? Solution: Are the four equations equivalent? YES melissa.stewart@hallco.org October 2013 What’s the main idea of Unit 4? • • • • Write expressions in equivalent forms to solve problems Analyze functions using different representations Build new functions from existing functions Construct and compare linear, quadratic, and exponential models and solve problems. Concepts & Skills to Maintain from Previous Grades The concept of a function Various representations of functions Exponential functions and characteristics of their graphs The solution of linear equations using algebra and graphing approaches Familiarity with graphing technology Use patterns to write a function to model a situation Websites to help with the above: http://www.crctlessons.com/ www.aplusmath.com www.aaamath.com Enduring Understandings from this Unit There is an inverse relationship between exponents and logarithms. Logarithms can be used to solve exponential equations. An exponential equation can be written as a logarithmic equation; a logarithmic equation can be written as an exponential equation. Two special logarithmic functions are the common logarithmic function and the natural logarithmic function. These special functions occur often in nature. Common logarithms and natural logarithms can be used to evaluate logarithms with bases other than 10 or . melissa.stewart@hallco.org October 2013 Examples & Explanations Problem 1: A hospital is conducting a study to see how different environmental conditions influence the growth of streptococcus pneumonia. Explain in terms of the structure of the expressions defining and , why these two populations never share the same value at any time during the experiment. Solution: and grows at a rate based on and grows at a rate based on Since and , > melissa.stewart@hallco.org October 2013 Problem 2: By definition yield ( is the exponent which must be raised in order to ). Use this definition to compute: Solution: melissa.stewart@hallco.org October 2013 Problem 3: Graphene is a 1 atom thick layer of graphite with many interesting properties and uses. Suppose the thickness of graphene is 200 picometers: one picometer is one trillionth of a meter. About how many times would you have to split a 1 mm thick sample of graphite in half in order to get a single layer of graphene? Solution: picometers in one millimeter. Cutting in half times yield a thickness of millimeters or picometers. Problem 4: What is the relationship between the graphs of exponential functions and logarithmic functions? Solution: By analyzing the graph, they are inverses. melissa.stewart@hallco.org October 2013 The student edition for Unit 4 can be found at https://www.georgiastandards.org/Common-Core/Pages/Math-9-12.aspx On the left side, please look under mathematics, Accelerated Geometry B/Advanced Algebra. Then, the right side has a pull-down menu to access the units. Additional parent guides will be posted to the parent resource page on http://www.hallco.org/boe/index.php (right hand menu) as they become available. melissa.stewart@hallco.org October 2013