
Mathematics with Applications In the Management, Natural, and Social Sciences (12th Edition)
12th Edition
ISBN: 9780134767628
Author: Margaret L. Lial, Thomas W. Hungerford, John P. Holcomb, Bernadette Mullins
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 4.4, Problem 70E
Work these problems. (See Examples 6, 7, and 8.)
Number of Teachers Thetotal number of teachers in the United Sates (in millions) can be approximated by the function
where
a. Find the number of teachers in the year 2013.
b. Find the first full year in which the number of teachers exceeded 3.0 million.
Expert Solution & Answer

Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Evaluate the definite integral using the given integration limits and the limits obtained by trigonometric substitution.
14
x²
dx
249
(a) the given integration limits
(b) the limits obtained by trigonometric substitution
I am completely lost in how to answer this question. Please help with as many details. Thank you
Please help with 4f) thanks
Chapter 4 Solutions
Mathematics with Applications In the Management, Natural, and Social Sciences (12th Edition)
Ch. 4.1 - Checkpoint 1
(a) Fill in this table:
x g(x) =...Ch. 4.1 - Prob. 2CPCh. 4.1 - Checkpoint 3
Use a graphing calculator to graph ...Ch. 4.1 - Prob. 4CPCh. 4.1 - Checkpoint 5
Graph
Ch. 4.1 - Prob. 6CPCh. 4.1 - Checkpoint 7 Per-person wine consumption (in...Ch. 4.1 - Classify each function as linear, quadratic, or...Ch. 4.1 - Prob. 2ECh. 4.1 - Prob. 3E
Ch. 4.1 - Prob. 4ECh. 4.1 - Classify each function as linear, quadratic, or...Ch. 4.1 - Prob. 6ECh. 4.1 - Without graphing,
(a) describe the shape of the...Ch. 4.1 - Prob. 8ECh. 4.1 - Prob. 9ECh. 4.1 - Prob. 10ECh. 4.1 - Without graphing,
(a) describe the shape of the...Ch. 4.1 - Prob. 12ECh. 4.1 - Graph each function. (See Examples 1–3.)
13.
Ch. 4.1 - Prob. 14ECh. 4.1 - Graph each function. (See Examples 1–3.)
15.
Ch. 4.1 - Prob. 16ECh. 4.1 - Graph each function. (See Examples 1–3.)
17.
Ch. 4.1 - Prob. 18ECh. 4.1 - Prob. 19ECh. 4.1 - Prob. 20ECh. 4.1 - Prob. 21ECh. 4.1 - Prob. 22ECh. 4.1 - Prob. 23ECh. 4.1 - Prob. 24ECh. 4.1 - Prob. 25ECh. 4.1 - Prob. 26ECh. 4.1 - In Exercises 27 and 28, the graph of an...Ch. 4.1 - Prob. 28ECh. 4.1 - Prob. 29ECh. 4.1 - 30. Give a rule of the form to define the...Ch. 4.1 - Prob. 31ECh. 4.1 - Prob. 32ECh. 4.1 - Prob. 33ECh. 4.1 - Prob. 34ECh. 4.1 - Prob. 35ECh. 4.1 - 36. Finance If money loses value at the rate of 3%...Ch. 4.1 - Work these problems. (See Example 5.)
37. Finance...Ch. 4.1 - 38. Natural Science Biologists have found that the...Ch. 4.1 - Work the following exercises.
39. Prudential...Ch. 4.1 - 40. Business The monthly payment on a car loan at...Ch. 4.1 - 41. Natural Science The amount of plutonium...Ch. 4.1 - Business The scrap value of a machine is the value...Ch. 4.1 - Business The scrap value of a machine is the value...Ch. 4.1 - Business The scrap value of a machine is the value...Ch. 4.1 - Work the following problems. (See Examples 5 and...Ch. 4.1 - Work the following problems. (See Examples 5 and...Ch. 4.1 -
GDP Use the following information to answer...Ch. 4.1 -
GDP Use the following information to answer...Ch. 4.1 - GDP Use the following information to answer...Ch. 4.1 -
GDP Use the following information to answer...Ch. 4.1 - Asset Management The amount of money (in trillions...Ch. 4.1 - Imports from Vietnam The value of U.S. imports...Ch. 4.1 -
53. Subprime Mortgages The amount of money (in...Ch. 4.1 - Subprime Mortgages The amount of money (in...Ch. 4.2 - Checkpoint 1
Suppose the number of bacteria in a...Ch. 4.2 - Checkpoint 2
Suppose an investment grows...Ch. 4.2 - Prob. 3CPCh. 4.2 - Prob. 4CPCh. 4.2 - Prob. 1ECh. 4.2 - 2. Finance Suppose you owe $1500 on your credit...Ch. 4.2 - Natural Gas Production Theannual amount of energy...Ch. 4.2 - Oil Production The annual amount of U.S. crude-oil...Ch. 4.2 - In each of the following problems, find an...Ch. 4.2 - 6. Social Science The U.S. Census Bureau predicts...Ch. 4.2 -
In each of the following problems, find an...Ch. 4.2 -
In each of the following problems, find an...Ch. 4.2 - In the following exercises, find the exponential...Ch. 4.2 - Prob. 10ECh. 4.2 - In the following exercises, find the exponential...Ch. 4.2 - In the following exercises, find the exponential...Ch. 4.2 - 13. Business Assembly-line operations tend to have...Ch. 4.2 - 14. Social Science The number of words per minute...Ch. 4.2 - Natural Science Newton's law of cooling says that...Ch. 4.2 - Natural Science Newton's law of cooling says that...Ch. 4.2 - Internet Use in China The percentage of Chinese...Ch. 4.2 - Seat-Belt Use Data form the National Highway...Ch. 4.2 - Food Assistance The amount of money the U.S....Ch. 4.2 - Prob. 20ECh. 4.2 - Prob. 21ECh. 4.2 - Prob. 22ECh. 4.3 - Checkpoint 1
Find each common logarithm.
(a) log...Ch. 4.3 - Prob. 2CPCh. 4.3 - Prob. 3CPCh. 4.3 - Prob. 4CPCh. 4.3 - Prob. 5CPCh. 4.3 - Prob. 6CPCh. 4.3 - Prob. 8CPCh. 4.3 - Prob. 1ECh. 4.3 - Complete each statement in Exercises 1–4.
2. The...Ch. 4.3 - Complete each statement in Exercises 1–4.
3. What...Ch. 4.3 - Complete each statement in Exercises...Ch. 4.3 - Translate each logarithmic statement into an...Ch. 4.3 - Translate each logarithmic statement into an...Ch. 4.3 - Translate each logarithmic statement into an...Ch. 4.3 - Translate each logarithmic statement into an...Ch. 4.3 - Translate each exponential statement. into an...Ch. 4.3 - Translate each exponential statement into an...Ch. 4.3 - Translate each exponential statement into an...Ch. 4.3 - Translate each exponential statement into an...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Without using a calculator, evaluate each of the...Ch. 4.3 - Use a calculator to evaluate each logarithm to...Ch. 4.3 - Use a calculator to evaluate each logarithm to...Ch. 4.3 - Use a calculator to evaluate each logarithm to...Ch. 4.3 - Use a calculator to evaluate each logarithm to...Ch. 4.3 - 29. Why does 1 always equal 0 for any valid base...Ch. 4.3 - Prob. 30ECh. 4.3 - Write each expression as the logarithm of a single...Ch. 4.3 - Prob. 32ECh. 4.3 - Prob. 33ECh. 4.3 - Write each expression as the logarithm of a single...Ch. 4.3 - Write each expression as the logarithm of a single...Ch. 4.3 - Write each expression as the logarithm of a single...Ch. 4.3 - Write each expression as the logarithm of a single...Ch. 4.3 - Write each expression as a sum and/or a difference...Ch. 4.3 - Write each expression as a sum and/or a difference...Ch. 4.3 - Write each expression as a sum and/or a difference...Ch. 4.3 - Write each expression as a sum and/or a difference...Ch. 4.3 - Write each expression as a sum and/or a difference...Ch. 4.3 - Express each expression in terms of u and v, where...Ch. 4.3 - Express each expression in terms of u and v, where...Ch. 4.3 - Express each expression in terms of u and v, where...Ch. 4.3 - Express each expression in terms of u and v, where...Ch. 4.3 - Evaluate each expression. (See Example 9.)
Example...Ch. 4.3 - Evaluate each expression. (See Example 9.)
Example...Ch. 4.3 - Evaluate each expression. (See Example 9.)
Example...Ch. 4.3 - Prob. 50ECh. 4.3 - Prob. 51ECh. 4.3 - Prob. 52ECh. 4.3 - Prob. 53ECh. 4.3 - Prob. 54ECh. 4.3 - Prob. 55ECh. 4.3 - Prob. 56ECh. 4.3 - Prob. 57ECh. 4.3 - Prob. 58ECh. 4.3 - Prob. 59ECh. 4.3 - Prob. 60ECh. 4.3 - Prob. 61ECh. 4.3 - 62. Health Two people with flu visited a college...Ch. 4.3 - Health Insurance Costs The average annual cost (in...Ch. 4.3 - Prob. 64ECh. 4.3 - Dairy Expenditures The average annual expenditures...Ch. 4.3 - Credit Union Assets The total assets (in billions...Ch. 4.3 - Border Patrol Budget The amount (in billions) that...Ch. 4.3 - Opioid Deaths The number of deaths from opioids in...Ch. 4.3 - 69. Apple iPhone Sales The worldwide number (in...Ch. 4.3 - Prob. 70ECh. 4.4 - Checkpoint 1
Solve each equation.
(a)
(b)
Ch. 4.4 - Prob. 2CPCh. 4.4 - Prob. 3CPCh. 4.4 - Prob. 4CPCh. 4.4 - Prob. 5CPCh. 4.4 - Checkpoint 6
Solve each equation. Round solutions...Ch. 4.4 - Prob. 7CPCh. 4.4 - Prob. 8CPCh. 4.4 - Prob. 9CPCh. 4.4 - Prob. 10CPCh. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Prob. 2ECh. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Solve each logarithmic equation. (See Example...Ch. 4.4 - Prob. 16ECh. 4.4 - Prob. 17ECh. 4.4 - Prob. 18ECh. 4.4 - Prob. 19ECh. 4.4 - Prob. 20ECh. 4.4 - 21. Suppose you overhear the following statement:...Ch. 4.4 - Prob. 22ECh. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Solve these exponential equations without using...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Use logarithms to solve these exponential...Ch. 4.4 - Prob. 41ECh. 4.4 - Prob. 42ECh. 4.4 - Prob. 43ECh. 4.4 - Prob. 44ECh. 4.4 - Prob. 45ECh. 4.4 - Prob. 46ECh. 4.4 - Prob. 47ECh. 4.4 - Prob. 48ECh. 4.4 - Prob. 49ECh. 4.4 - Prob. 50ECh. 4.4 - Prob. 51ECh. 4.4 - Prob. 52ECh. 4.4 - Solve these equations. (See Examples 1–6.)
53.
Ch. 4.4 - Prob. 54ECh. 4.4 - Prob. 55ECh. 4.4 - Prob. 56ECh. 4.4 - Prob. 57ECh. 4.4 - Prob. 58ECh. 4.4 - Solve these equations. (See Examples 1−6.)
59.
Ch. 4.4 - Prob. 60ECh. 4.4 - Prob. 61ECh. 4.4 - Prob. 62ECh. 4.4 - Work these problems. (See Examples 6, 7, and...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and 8.)...Ch. 4.4 - Work these problems. (See Examples 6, 7, and...Ch. 4.4 - Work these exercises. (See Example 8.)
Example...Ch. 4.4 - Prob. 76ECh. 4.4 - Prob. 77ECh. 4.4 - Prob. 78ECh. 4.4 - Prob. 79ECh. 4.4 - Prob. 80ECh. 4.4 - Prob. 81ECh. 4.4 - Prob. 82ECh. 4 - Match each equation with the letter of the graph...Ch. 4 - Prob. 2RECh. 4 - Prob. 3RECh. 4 - Prob. 4RECh. 4 - Prob. 5RECh. 4 - Prob. 6RECh. 4 - Consider the exponential function y = f(x) = ax...Ch. 4 - Prob. 8RECh. 4 - Prob. 9RECh. 4 - Prob. 10RECh. 4 - Prob. 11RECh. 4 - Prob. 12RECh. 4 - Prob. 13RECh. 4 - Prob. 14RECh. 4 - Prob. 15RECh. 4 - Prob. 16RECh. 4 - Prob. 17RECh. 4 - Prob. 18RECh. 4 - Prob. 19RECh. 4 - Prob. 20RECh. 4 - Prob. 21RECh. 4 - Prob. 22RECh. 4 - Prob. 23RECh. 4 - Prob. 24RECh. 4 - Prob. 25RECh. 4 - Evaluate these expressions without using a...Ch. 4 - Prob. 27RECh. 4 - Prob. 28RECh. 4 - Prob. 29RECh. 4 - Prob. 30RECh. 4 - Prob. 31RECh. 4 - Prob. 32RECh. 4 - Prob. 33RECh. 4 - Prob. 34RECh. 4 - Prob. 35RECh. 4 - Prob. 36RECh. 4 - Prob. 37RECh. 4 - Prob. 38RECh. 4 - Prob. 39RECh. 4 - Prob. 40RECh. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - 48.
Solve each equation. Round to the nearest...Ch. 4 - Prob. 49RECh. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Solve each equation. Round to the nearest...Ch. 4 - Prob. 53RECh. 4 - Prob. 54RECh. 4 - Prob. 55RECh. 4 - Prob. 56RECh. 4 - Prob. 57RECh. 4 - Prob. 58RECh. 4 - Prob. 59RECh. 4 - Prob. 60RECh. 4 - Prob. 61RECh. 4 - Prob. 62RECh. 4 - Prob. 63RECh. 4 - Prob. 64RECh. 4 - Prob. 65RECh. 4 - Prob. 66RECh. 4 - Prob. 67RECh. 4 - Prob. 68RECh. 4 - For Exercises 1–6, use Equation (1) that provides...Ch. 4 - Prob. 2CECh. 4 - For Exercises 16, use Equation (1) that provides a...Ch. 4 - For Exercises 1–6, use Equation (1) that provides...Ch. 4 - For Exercises 1–6, use Equation (1) that provides...Ch. 4 - For Exercises 1–6, use Equation (1) that provides...Ch. 4 - For Exercises 710, use the model in Equation (2)...Ch. 4 - For Exercises 7–10, use the model in Equation (2)...Ch. 4 - For Exercises 7–10, use the model in Equation (2)...Ch. 4 - For Exercises 7–10, use the model in Equation (2)...Ch. 4 - For Exercises 1114, use the model in Equation (3)...Ch. 4 - Prob. 12CECh. 4 - Prob. 13CECh. 4 - For Exercises 11–14, use the model in Equation (3)...Ch. 4 - Prob. 1EPCh. 4 - Prob. 2EPCh. 4 - Prob. 3EP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, subject and related others by exploring similar questions and additional content below.Similar questions
- I do not understand what this means can you please help. Thanksarrow_forwardPlease help with 4e) thanksarrow_forwardPage of 2 Zoom Name: _______________Project Wacko-pediaWacko-podia is an Internet encyclopedia (OK, I admit I made Wacko-podia up for this project, anyway)that uses an automated system based on logic to determine whether a new entry will be entered intheir website. Unfortunately, sometimes inaccurate information can get entered because the statementhas a “True” truth value even if there is incorrect information in part of the statement. For eachstatement below, determine if the entry will get past the automated system or will be labeled with a“False” truth value and end up being returned to the sender.Notes:1. You may need to look up some information in an almanac or other trustworthy onlinereference.2. Work must be shown to receive credit.Statement A: The capital of Pennsylvania is Pittsburgh or the capital of Kentucky is Frankfort.p: Truth Value of p:q: Truth Value of q:Translation of compound statement into symbols:Work:Conclusion: Entered __?…arrow_forward
- Please help with 18 d) with as much detail. Thanksarrow_forwardPlease help with 18 c) with as much detail. Thanksarrow_forwardPage of 2 ZOOM + 1) a) Answer the following questions by circling TRUE or FALSE (No explanation or work required). [1 0 0 i) A = 0 2 6 is invertible. (TRUE FALSE) LO -4-12] ii) We can use the transpose of the cofactor matrix to find the inverse of a matrix. (TRUE FALSE) = iii) If A 2, and A is a 5x5 square matrix, |2A] = 64. (TRUE FALSE) iv) Every vector space must contain two trivial subspaces. (TRUE FALSE) v) The set of all integers with standard operations is a vector space. (TRUE FALSE) b) Write v as a linear combination of the vectors in the set S, if possible, where v=(1,-4), and S={(1,2),(1,-1)}. 2) a) Solve the following system of linear equations using Cramer's Rule and check the correctness of your answer. 4xyz 1 2x + 2y + 3z = 10 5x-2y-2z = -1 b) Find the adjoint of the following matrix A. Then use the adjoint to find the inverse of A if possible, and check the correctness of your answer. A = c) Determine whether the following points are collinear. Why or why not? If not,…arrow_forward
- A boat's value over time, x, is given as the function f(x) = 400(b)x. Graph the boat's value decreasing at a rate of 25% per year?arrow_forwardAssignment #1 Q1: Test the following series for convergence. Specify the test you use: 1 n+5 (-1)n a) Σn=o √n²+1 b) Σn=1 n√n+3 c) Σn=1 (2n+1)3 3n 1 d) Σn=1 3n-1 e) Σn=1 4+4narrow_forwardDescribe the y-intercept and end behavior of the following graph: 0 2 4 -2 -4 -6arrow_forward
- Computing Ending Inventory under Dollar-Value LIFO Wheels Inc. accounts for inventory using the dollar-value LIFO method. The following information is available for Year 1 through Year 3 (listed chronologically). Year Ending Inventory at FIFO Price Index Year 1 Year 2 Year 3 $6,000 1.00 9,600 1.10 12,000 1.13 Compute ending inventory under the dollar-value LIFO method for Year 1, Year 2, and Year 3. • Note: Round your answers to the nearest whole dollar.arrow_forwardUpland Co.'s inventory records showed the following data accounted for in a perpetual inventory system. Unit Date June 1 Units Cost Inventory (beg.) 700 $8.00 June 3 Purchases 1,400 8.40 June 7 Sales (at $16 per unit) 980 952 9.00 June 20 Purchases June 22 Sales (at $16 per unit) 1,540 What is (a) ending inventory on June 30, and (b) cost of goods sold for June, using the FIFO inventory method? •Note: Do not use negative signs with any of your answers. •Note: List the inventory units in chronological order based on their purchase date with beginning inventory, if any, listed first.arrow_forwardanswer problem 1a, 1b, 1c, 1d, and 1e and show work/ explain how you got the answerarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
- College AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningAlgebra and Trigonometry (MindTap Course List)AlgebraISBN:9781305071742Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage

College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning

Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill


College Algebra
Algebra
ISBN:9781305115545
Author:James Stewart, Lothar Redlin, Saleem Watson
Publisher:Cengage Learning

Algebra and Trigonometry (MindTap Course List)
Algebra
ISBN:9781305071742
Author:James Stewart, Lothar Redlin, Saleem Watson
Publisher:Cengage Learning
The Shape of Data: Distributions: Crash Course Statistics #7; Author: CrashCourse;https://www.youtube.com/watch?v=bPFNxD3Yg6U;License: Standard YouTube License, CC-BY
Shape, Center, and Spread - Module 20.2 (Part 1); Author: Mrmathblog;https://www.youtube.com/watch?v=COaid7O_Gag;License: Standard YouTube License, CC-BY
Shape, Center and Spread; Author: Emily Murdock;https://www.youtube.com/watch?v=_YyW0DSCzpM;License: Standard Youtube License