The Power in Numbers: a Logarithms Refresher
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Inverse of Exponential Functions Are Logarithmic Functions
Math Instructional Framework Full Name Math III Unit 3 Lesson 2 Time Frame Unit Name Logarithmic Functions as Inverses of Exponential Functions Learning Task/Topics/ Task 2: How long Does It Take? Themes Task 3: The Population of Exponentia Task 4: Modeling Natural Phenomena on Earth Culminating Task: Traveling to Exponentia Standards and Elements MM3A2. Students will explore logarithmic functions as inverses of exponential functions. c. Define logarithmic functions as inverses of exponential functions. Lesson Essential Questions How can you graph the inverse of an exponential function? Activator PROBLEM 2.Task 3: The Population of Exponentia (Problem 1 could be completed prior) Work Session Inverse of Exponential Functions are Logarithmic Functions A Graph the inverse of exponential functions. B Graph logarithmic functions. See Notes Below. VOCABULARY Asymptote: A line or curve that describes the end behavior of the graph. A graph never crosses a vertical asymptote but it may cross a horizontal or oblique asymptote. Common logarithm: A logarithm with a base of 10. A common logarithm is the power, a, such that 10a = b. The common logarithm of x is written log x. For example, log 100 = 2 because 102 = 100. Exponential functions: A function of the form y = a·bx where a > 0 and either 0 < b < 1 or b > 1. Logarithmic functions: A function of the form y = logbx, with b 1 and b and x both positive. A logarithmic x function is the inverse of an exponential function. The inverse of y = b is y = logbx. Logarithm: The logarithm base b of a number x, logbx, is the power to which b must be raised to equal x. -
Decimal Rounding
Mathematics Instructional Plan – Grade 5 Decimal Rounding Strand: Number and Number Sense Topic: Rounding decimals, through the thousandths, to the nearest whole number, tenth, or hundredth. Primary SOL: 5.1 The student, given a decimal through thousandths, will round to the nearest whole number, tenth, or hundredth. Materials Base-10 blocks Decimal Rounding activity sheet (attached) “Highest or Lowest” Game (attached) Open Number Lines activity sheet (attached) Ten-sided number generators with digits 0–9, or decks of cards Vocabulary approximate, between, closer to, decimal number, decimal point, hundredth, rounding, tenth, thousandth, whole Student/Teacher Actions: What should students be doing? What should teachers be doing? 1. Begin with a review of decimal place value: Display a decimal in the thousandths place, such as 34.726, using base-10 blocks. In pairs, have students discuss how to read the number using place-value names, and review the decimal place each digit holds. Briefly have students share their thoughts with the class by asking: What digit is in the tenths place? The hundredths place? The thousandths place? Who would like to share how to say this decimal using place value? 2. Ask, “If this were a monetary amount, $34.726, how would we determine the amount to the nearest cent?” Allow partners or small groups to discuss this question. It may be helpful if students underlined the place that indicates cents (the hundredths place) in order to keep track of the rounding place. Distribute the Open Number Lines activity sheet and display this number line on the board. Guide students to recall that the nearest cent is the same as the nearest hundredth of a dollar. -
Unit 2. Powers, Roots and Logarithms
English Maths 4th Year. European Section at Modesto Navarro Secondary School UNIT 2. POWERS, ROOTS AND LOGARITHMS. 1. POWERS. 1.1. DEFINITION. When you multiply two or more numbers, each number is called a factor of the product. When the same factor is repeated, you can use an exponent to simplify your writing. An exponent tells you how many times a number, called the base, is used as a factor. A power is a number that is expressed using exponents. In English: base ………………………………. Exponente ………………………… Other examples: . 52 = 5 al cuadrado = five to the second power or five squared . 53 = 5 al cubo = five to the third power or five cubed . 45 = 4 elevado a la quinta potencia = four (raised) to the fifth power . 1521 = fifteen to the twenty-first . 3322 = thirty-three to the power of twenty-two Exercise 1. Calculate: a) (–2)3 = f) 23 = b) (–3)3 = g) (–1)4 = c) (–5)4 = h) (–5)3 = d) (–10)3 = i) (–10)6 = 3 3 e) (7) = j) (–7) = Exercise: Calculate with the calculator: a) (–6)2 = b) 53 = c) (2)20 = d) (10)8 = e) (–6)12 = For more information, you can visit http://en.wikibooks.org/wiki/Basic_Algebra UNIT 2. Powers, roots and logarithms. 1 English Maths 4th Year. European Section at Modesto Navarro Secondary School 1.2. PROPERTIES OF POWERS. Here are the properties of powers. Pay attention to the last one (section vii, powers with negative exponent) because it is something new for you: i) Multiplication of powers with the same base: E.g.: ii) Division of powers with the same base : E.g.: E.g.: 35 : 34 = 31 = 3 iii) Power of a power: 2 E.g. -
IEEE Standard 754 for Binary Floating-Point Arithmetic
Work in Progress: Lecture Notes on the Status of IEEE 754 October 1, 1997 3:36 am Lecture Notes on the Status of IEEE Standard 754 for Binary Floating-Point Arithmetic Prof. W. Kahan Elect. Eng. & Computer Science University of California Berkeley CA 94720-1776 Introduction: Twenty years ago anarchy threatened floating-point arithmetic. Over a dozen commercially significant arithmetics boasted diverse wordsizes, precisions, rounding procedures and over/underflow behaviors, and more were in the works. “Portable” software intended to reconcile that numerical diversity had become unbearably costly to develop. Thirteen years ago, when IEEE 754 became official, major microprocessor manufacturers had already adopted it despite the challenge it posed to implementors. With unprecedented altruism, hardware designers had risen to its challenge in the belief that they would ease and encourage a vast burgeoning of numerical software. They did succeed to a considerable extent. Anyway, rounding anomalies that preoccupied all of us in the 1970s afflict only CRAY X-MPs — J90s now. Now atrophy threatens features of IEEE 754 caught in a vicious circle: Those features lack support in programming languages and compilers, so those features are mishandled and/or practically unusable, so those features are little known and less in demand, and so those features lack support in programming languages and compilers. To help break that circle, those features are discussed in these notes under the following headings: Representable Numbers, Normal and Subnormal, Infinite -
How to Enter Answers in Webwork
Introduction to WeBWorK 1 How to Enter Answers in WeBWorK Addition + a+b gives ab Subtraction - a-b gives ab Multiplication * a*b gives ab Multiplication may also be indicated by a space or juxtaposition, such as 2x, 2 x, 2*x, or 2(x+y). Division / a a/b gives b Exponents ^ or ** a^b gives ab as does a**b Parentheses, brackets, etc (...), [...], {...} Syntax for entering expressions Be careful entering expressions just as you would be careful entering expressions in a calculator. Sometimes using the * symbol to indicate multiplication makes things easier to read. For example (1+2)*(3+4) and (1+2)(3+4) are both valid. So are 3*4 and 3 4 (3 space 4, not 34) but using an explicit multiplication symbol makes things clearer. Use parentheses (), brackets [], and curly braces {} to make your meaning clear. Do not enter 2/4+5 (which is 5 ½ ) when you really want 2/(4+5) (which is 2/9). Do not enter 2/3*4 (which is 8/3) when you really want 2/(3*4) (which is 2/12). Entering big quotients with square brackets, e.g. [1+2+3+4]/[5+6+7+8], is a good practice. Be careful when entering functions. It is always good practice to use parentheses when entering functions. Write sin(t) instead of sint or sin t. WeBWorK has been programmed to accept sin t or even sint to mean sin(t). But sin 2t is really sin(2)t, i.e. (sin(2))*t. Be careful. Be careful entering powers of trigonometric, and other, functions. -
Variables and Calculations
¡ ¢ £ ¤ ¥ ¢ ¤ ¦ § ¨ © © § ¦ © § © ¦ £ £ © § ! 3 VARIABLES AND CALCULATIONS Now you’re ready to learn your first ele- ments of Python and start learning how to solve programming problems. Although programming languages have myriad features, the core parts of any programming language are the instructions that perform numerical calculations. In this chapter, we’ll explore how math is performed in Python programs and learn how to solve some prob- lems using only mathematical operations. ¡ ¢ £ ¤ ¥ ¢ ¤ ¦ § ¨ © © § ¦ © § © ¦ £ £ © § ! Sample Program Let’s start by looking at a very simple problem and its Python solution. PROBLEM: THE TOTAL COST OF TOOTHPASTE A store sells toothpaste at $1.76 per tube. Sales tax is 8 percent. For a user-specified number of tubes, display the cost of the toothpaste, showing the subtotal, sales tax, and total, including tax. First I’ll show you a program that solves this problem: toothpaste.py tube_count = int(input("How many tubes to buy: ")) toothpaste_cost = 1.76 subtotal = toothpaste_cost * tube_count sales_tax_rate = 0.08 sales_tax = subtotal * sales_tax_rate total = subtotal + sales_tax print("Toothpaste subtotal: $", subtotal, sep = "") print("Tax: $", sales_tax, sep = "") print("Total is $", total, " including tax.", sep = ") Parts of this program may make intuitive sense to you already; you know how you would answer the question using a calculator and a scratch pad, so you know that the program must be doing something similar. Over the next few pages, you’ll learn exactly what’s going on in these lines of code. For now, enter this program into your Python editor exactly as shown and save it with the required .py extension. Run the program several times with different responses to the question to verify that the program works. -
Introduction to the Python Language
Introduction to the Python language CS111 Computer Programming Department of Computer Science Wellesley College Python Intro Overview o Values: 10 (integer), 3.1415 (decimal number or float), 'wellesley' (text or string) o Types: numbers and text: int, float, str type(10) Knowing the type of a type('wellesley') value allows us to choose the right operator when o Operators: + - * / % = creating expressions. o Expressions: (they always produce a value as a result) len('abc') * 'abc' + 'def' o Built-in functions: max, min, len, int, float, str, round, print, input Python Intro 2 Concepts in this slide: Simple Expressions: numerical values, math operators, Python as calculator expressions. Input Output Expressions Values In [...] Out […] 1+2 3 3*4 12 3 * 4 12 # Spaces don't matter 3.4 * 5.67 19.278 # Floating point (decimal) operations 2 + 3 * 4 14 # Precedence: * binds more tightly than + (2 + 3) * 4 20 # Overriding precedence with parentheses 11 / 4 2.75 # Floating point (decimal) division 11 // 4 2 # Integer division 11 % 4 3 # Remainder 5 - 3.4 1.6 3.25 * 4 13.0 11.0 // 2 5.0 # output is float if at least one input is float 5 // 2.25 2.0 5 % 2.25 0.5 Python Intro 3 Concepts in this slide: Strings and concatenation string values, string operators, TypeError A string is just a sequence of characters that we write between a pair of double quotes or a pair of single quotes. Strings are usually displayed with single quotes. The same string value is created regardless of which quotes are used. -
The Logarithmic Chicken Or the Exponential Egg: Which Comes First?
The Logarithmic Chicken or the Exponential Egg: Which Comes First? Marshall Ransom, Senior Lecturer, Department of Mathematical Sciences, Georgia Southern University Dr. Charles Garner, Mathematics Instructor, Department of Mathematics, Rockdale Magnet School Laurel Holmes, 2017 Graduate of Rockdale Magnet School, Current Student at University of Alabama Background: This article arose from conversations between the first two authors. In discussing the functions ln(x) and ex in introductory calculus, one of us made good use of the inverse function properties and the other had a desire to introduce the natural logarithm without the classic definition of same as an integral. It is important to introduce mathematical topics using a minimal number of definitions and postulates/axioms when results can be derived from existing definitions and postulates/axioms. These are two of the ideas motivating the article. Thus motivated, the authors compared manners with which to begin discussion of the natural logarithm and exponential functions in a calculus class. x A related issue is the use of an integral to define a function g in terms of an integral such as g()() x f t dt . c We believe that this is something that students should understand and be exposed to prior to more advanced x x sin(t ) 1 “surprises” such as Si(x ) dt . In particular, the fact that ln(x ) dt is extremely important. But t t 0 1 must that fact be introduced as a definition? Can the natural logarithm function arise in an introductory calculus x 1 course without the -
Rcttutorial1.Pdf
R Tutorial 1 Introduction to Computational Science: Modeling and Simulation for the Sciences, 2nd Edition Angela B. Shiflet and George W. Shiflet Wofford College © 2014 by Princeton University Press R materials by Stephen Davies, University of Mary Washington [email protected] Introduction R is one of the most powerful languages in the world for computational science. It is used by thousands of scientists, researchers, statisticians, and mathematicians across the globe, and also by corporations such as Google, Microsoft, the Mozilla foundation, the New York Times, and Facebook. It combines the power and flexibility of a full-fledged programming language with an exhaustive battery of statistical analysis functions, object- oriented support, and eye-popping, multi-colored, customizable graphics. R is also open source! This means two important things: (1) R is, and always will be, absolutely free, and (2) it is supported by a great body of collaborating developers, who are continually improving R and adding to its repertoire of features. To find out more about how you can download, install, use, and contribute, to R, see http://www.r- project.org. Getting started Make sure that the R application is open, and that you have access to the R Console window. For the following material, at a prompt of >, type each example; and evaluate the statement in the Console window. To evaluate a command, press ENTER. In this document (but not in R), input is in red, and the resulting output is in blue. We start by evaluating 12-factorial (also written “12!”), which is the product of the positive integers from 1 through 12. -
Programming for Computations – Python
15 Svein Linge · Hans Petter Langtangen Programming for Computations – Python Editorial Board T. J.Barth M.Griebel D.E.Keyes R.M.Nieminen D.Roose T.Schlick Texts in Computational 15 Science and Engineering Editors Timothy J. Barth Michael Griebel David E. Keyes Risto M. Nieminen Dirk Roose Tamar Schlick More information about this series at http://www.springer.com/series/5151 Svein Linge Hans Petter Langtangen Programming for Computations – Python A Gentle Introduction to Numerical Simulations with Python Svein Linge Hans Petter Langtangen Department of Process, Energy and Simula Research Laboratory Environmental Technology Lysaker, Norway University College of Southeast Norway Porsgrunn, Norway On leave from: Department of Informatics University of Oslo Oslo, Norway ISSN 1611-0994 Texts in Computational Science and Engineering ISBN 978-3-319-32427-2 ISBN 978-3-319-32428-9 (eBook) DOI 10.1007/978-3-319-32428-9 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2016945368 Mathematic Subject Classification (2010): 26-01, 34A05, 34A30, 34A34, 39-01, 40-01, 65D15, 65D25, 65D30, 68-01, 68N01, 68N19, 68N30, 70-01, 92D25, 97-04, 97U50 © The Editor(s) (if applicable) and the Author(s) 2016 This book is published open access. Open Access This book is distributed under the terms of the Creative Commons Attribution-Non- Commercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, a link is provided to the Creative Commons license and any changes made are indicated. -
Efficient, Arbitrarily High Precision Hardware Logarithmic Arithmetic For
Efficient, arbitrarily high precision hardware logarithmic arithmetic for linear algebra Jeff Johnson Facebook AI Research Los Angeles, CA, United States [email protected] Abstract—The logarithmic number system (LNS) is arguably cannot easily apply precision reduction, such as hyperbolic not broadly used due to exponential circuit overheads for embedding generation [5] or structure from motion via matrix summation tables relative to arithmetic precision. Methods to factorization [6], yet provide high local data reuse potential. reduce this overhead have been proposed, yet still yield designs with high chip area and power requirements. Use remains limited The logarithmic number system (LNS) [7] can provide to lower precision or high multiply/add ratio cases, while much energy efficiency by eliminating hardware multipliers and of linear algebra (near 1:1 multiply/add ratio) does not qualify. dividers, yet maintains significant computational overhead We present a dual-base approximate logarithmic arithmetic with Gaussian logarithm functions needed for addition and comparable to floating point in use, yet unlike LNS it is easily subtraction. While reduced precision cases can limit them- fully pipelined, extendable to arbitrary precision with O(n2) overhead, and energy efficient at a 1:1 multiply/add ratio. selves to relatively small LUTs/ROMs, high precision LNS Compared to float32 or float64 vector inner product with FMA, require massive ROMs, linear interpolators and substantial our design is respectively 2.3× and 4.6× more energy efficient MUXes. Pipelining is difficult, requiring resource duplication in 7 nm CMOS. It depends on exp and log evaluation 5.4× and or handling variable latency corner cases as seen in [8]. -
1.1 Place Value, Rounding, Comparing Whole Numbers
1.1 Place Value, Rounding, Comparing Whole Numbers Place Value Example: The number 13,652,103 would look like Millions Thousands Ones Hundreds Tens Ones Hundreds Tens Ones Hundreds Tens Ones 1 3 6 5 2 1 0 3 We’d read this in groups of three digits, so this number would be written thirteen million six hundred fifty two thousand one hundred and three Example: What is the place value of 4 in 6,342,105? The 4 is in the ten-thousands place Example: Write the value of two million, five hundred thousand, thirty six 2,500,036 Rounding When we round to a place value, we are looking for the closest number that has zeros in the digits to the right. Example: Round 173 to the nearest ten. Since we are rounding to the nearest ten, we want a 0 in the ones place. The two possible values are 170 or 180. 173 is closer to 170, so we round to 170. Example: Round 97,870 to the nearest thousand. The nearest values are 97,000 and 98,000. The closer value is 98,000. Example: Round 5,950 to the nearest hundred. The nearest values are 5,900 or 6,000. 5,950 is exactly halfway between, so by convention we round up, to 6,000. Comparing To compare to values, we look at which has the largest value in the highest place value. Example: Which is larger: 126 or 132? Both numbers are the same in the hundreds place, so we look in the tens place.