FUNCTIONS+CHANGE -WEBASSIGN
FUNCTIONS+CHANGE -WEBASSIGN
6th Edition
ISBN: 9780357422496
Author: Crauder
Publisher: CENGAGE L
bartleby

Concept explainers

Differential Equations
Have you ever observed the movement of the satellites and rockets or how the planets go around the sun in their orbits? How will you determine their motion? Definitely they follow some scientific laws and these kinds of problems are framed as differentia…
bartleby

Videos

Textbook Question
Book Icon
Chapter 2.4, Problem 27E

Water Flea F. E Smith has reported on population growth of the water flea. In one experiment, he found that the time t, in days, required to reach a population of N is given by the relation

e 0.44 t = N N 0 ( 228 − N 0 228 − N ) 4.46 .

Here N 0 is the initial population size. If the initial population size is 50, how long is required for the population to grow to 125?

Expert Solution & Answer
Check Mark

Want to see the full answer?

Check out a sample textbook solution
Blurred answer
Previous
Chapter 2.4, Problem 26E
Next
Chapter 2.4, Problem 28E

Chapter 2 Solutions

FUNCTIONS+CHANGE -WEBASSIGN

Ch. 2.1 - If a coffee filter is dropped, its velocity after...Ch. 2.1 - Suppose one canoe rents for 40,and2 is taken off...Ch. 2.1 - A Saving Account You deposit money into a savings...Ch. 2.1 - Savings with regular Deposits Suppose you deposit...Ch. 2.1 - Paying Off a Credit Card Suppose you owe 15, 000...Ch. 2.1 - Buying Power The inflation rate tells us the...Ch. 2.1 - Economic Efficiency Marginal cost is the...Ch. 2.1 - Flesch Reading Ease The Flesch Reading Ease Test...Ch. 2.1 - Spache Readability Formula The Spache Readability...Ch. 2.1 - Weight Lifting Brzyckis formula is used by weight...
Ch. 2.1 - Harvard Step Test The Harvard Step Test was...Ch. 2.1 - Public High School Enrollment One model for the...Ch. 2.1 - Later Public High School Enrollment Here is a...Ch. 2.1 - Species-Area Relation The number of species of...Ch. 2.1 - Competition Two friends enjoy competing with each...Ch. 2.1 - Profit The profit P, in thousands of dollars that...Ch. 2.1 - Prob. 15ECh. 2.1 - Counting when Order Does Not Matter This is a...Ch. 2.1 - APR and EAR Recall that the APR the annual...Ch. 2.1 - An Amortization Table Suppose you borrow P dollars...Ch. 2.1 - Prob. 19ECh. 2.1 - Renting Motel Rooms You own a motel with 30 rooms,...Ch. 2.1 - Prob. 21ECh. 2.1 - A Population of Foxes A breeding group of foxes is...Ch. 2.1 - Falling with a parachute If an average-sized man...Ch. 2.1 - Rolling 4 Sixes If you roll N dice, then the...Ch. 2.1 - Prob. 25ECh. 2.1 - Profit with Varying Price The background for this...Ch. 2.1 - A Precocious Child and Her Blocks A child has 64...Ch. 2.1 - Renting Paddleboats An enterprise rents out...Ch. 2.1 - Growth in Length of Haddock D.S. Raitt found that...Ch. 2.1 - Discharge from a Fire Hose The discharge from a...Ch. 2.1 - Prob. 31ECh. 2.1 - Terminal Velocity Revisited In one of the early...Ch. 2.1 - Research Project Find a function given by formula...Ch. 2.1 - Making Tables and Comparing Functions In Exercises...Ch. 2.1 - Prob. 2SBECh. 2.1 - Prob. 3SBECh. 2.1 - Prob. 4SBECh. 2.1 - Prob. 5SBECh. 2.1 - Prob. 6SBECh. 2.1 - Prob. 7SBECh. 2.1 - Prob. 8SBECh. 2.1 - Prob. 9SBECh. 2.1 - Prob. 10SBECh. 2.1 - Prob. 11SBECh. 2.1 - Finding Limiting Values In Exercises S-11 through...Ch. 2.1 - Prob. 13SBECh. 2.1 - Prob. 14SBECh. 2.1 - Prob. 15SBECh. 2.1 - Prob. 16SBECh. 2.1 - Prob. 17SBECh. 2.1 - Prob. 18SBECh. 2.1 - Prob. 19SBECh. 2.1 - Prob. 20SBECh. 2.1 - Prob. 21SBECh. 2.1 - Prob. 22SBECh. 2.1 - Finding Limiting Values In Exercises S-11 through...Ch. 2.1 - Prob. 24SBECh. 2.1 - Finding Maxima and Minima In Exercises S-25...Ch. 2.1 - Prob. 26SBECh. 2.1 - Prob. 27SBECh. 2.1 - Prob. 28SBECh. 2.1 - Prob. 29SBECh. 2.1 - Prob. 30SBECh. 2.1 - Prob. 31SBECh. 2.1 - Prob. 32SBECh. 2.2 - TEST TOUR UNDERSTANDING FOR EXAMPLE 2.3 Suppose a...Ch. 2.2 - TEST TOUR UNDERSTANDING FOR EXAMPLE 2.4 Changes in...Ch. 2.2 - Continuous Compounding A certain investment is...Ch. 2.2 - Present Value: The present value P is the...Ch. 2.2 - Equity: When you use a mortgage to purchase a...Ch. 2.2 - Buying a Car: If you buy a 25,000 car at an APR of...Ch. 2.2 - Adult Weight from Puppy Weight There is a formula...Ch. 2.2 - Mosteller Formula for Body Surface Area: Body...Ch. 2.2 - Weekly Cost: The weekly cost of running a small...Ch. 2.2 - Average Speed: A commuter regularly drives 70...Ch. 2.2 - Resale Value: The resale value V, in dollars, of a...Ch. 2.2 - Profit The yearly profit P for a widget producer...Ch. 2.2 - Baking a Potato: A potato is placed in a preheated...Ch. 2.2 - Functional Response: The amount C of food consumed...Ch. 2.2 - Population Growth: The growth G of a population...Ch. 2.2 - Ohms Law: says that when electric current is...Ch. 2.2 - Prob. 15ECh. 2.2 - Monthly Payment for a Home: If you borrow 120,000...Ch. 2.2 - Prob. 17ECh. 2.2 - Alexanders Formula One interesting problem in the...Ch. 2.2 - Prob. 18.2ECh. 2.2 - Prob. 19ECh. 2.2 - Planet Growth The amount of growth of plants in an...Ch. 2.2 - Prob. 21ECh. 2.2 - Viewing Earth: Astronauts looking at Earth from a...Ch. 2.2 - Magazine Circulation: The circulation C of a...Ch. 2.2 - Prob. 24ECh. 2.2 - Buffalo: Waterton Lakes National Park of Canada,...Ch. 2.2 - Prob. 26ECh. 2.2 - Prob. 27ECh. 2.2 - Prob. 1SBECh. 2.2 - Prob. 2SBECh. 2.2 - Prob. 3SBECh. 2.2 - Prob. 4SBECh. 2.2 - Prob. 5SBECh. 2.2 - Prob. 6SBECh. 2.2 - Prob. 7SBECh. 2.2 - Prob. 8SBECh. 2.2 - Prob. 9SBECh. 2.2 - Prob. 10SBECh. 2.2 - Prob. 11SBECh. 2.2 - Finding Windows and Making Graphs: In Exercises...Ch. 2.2 - Prob. 13SBECh. 2.2 - Prob. 14SBECh. 2.2 - Prob. 15SBECh. 2.2 - Prob. 16SBECh. 2.2 - Prob. 17SBECh. 2.2 - Finding Windows and Making Graphs: In Exercises...Ch. 2.2 - Prob. 19SBECh. 2.2 - Prob. 20SBECh. 2.2 - Prob. 21SBECh. 2.2 - Prob. 22SBECh. 2.2 - Prob. 23SBECh. 2.2 - Prob. 24SBECh. 2.2 - Prob. 25SBECh. 2.2 - Prob. 26SBECh. 2.2 - Prob. 27SBECh. 2.2 - Prob. 28SBECh. 2.2 - Prob. 29SBECh. 2.2 - Finding Windows and Making Graphs: In Exercises...Ch. 2.3 - In the situation of the example, how long could...Ch. 2.3 - If you travel 300 miles on the first day and then...Ch. 2.3 - Prob. 3TUCh. 2.3 - Prob. 1ECh. 2.3 - Trans Fat You are ordering fast food for your...Ch. 2.3 - Prob. 3ECh. 2.3 - Prob. 4ECh. 2.3 - Break-even Point A manufacturer of T-shirts has...Ch. 2.3 - Juice Sales The number J, in thousands, of cans of...Ch. 2.3 - Resale Value The resale value V, in thousands of...Ch. 2.3 - Aerobic Power Aerobic power can be thought of as...Ch. 2.3 - Gas Mileage The distance d, in miles, that you can...Ch. 2.3 - Isocost Equation We are to buy quantities of two...Ch. 2.3 - Supply and Demand The quantity S of barley, in...Ch. 2.3 - Stock Turnover at Retail In retail sales, an...Ch. 2.3 - Prob. 13ECh. 2.3 - Sales Strategy A small business is considering...Ch. 2.3 - Prob. 15ECh. 2.3 - Prob. 16ECh. 2.3 - Temperature Conversions In everyday experience,...Ch. 2.3 - The Ideal Gas Law A mole of a chemical is a fixed...Ch. 2.3 - Running Ants A scientist observed that the speed S...Ch. 2.3 - Tax Owed According to the Oklahoma Income Tax...Ch. 2.3 - Prob. 21ECh. 2.3 - Growth in Weight and Height Between the ages of 7...Ch. 2.3 - Prob. 23ECh. 2.3 - Prob. 24ECh. 2.3 - Prob. 25ECh. 2.3 - Prob. 26ECh. 2.3 - Prob. 27ECh. 2.3 - Prob. 1SBECh. 2.3 - Prob. 2SBECh. 2.3 - Prob. 3SBECh. 2.3 - Prob. 4SBECh. 2.3 - Prob. 5SBECh. 2.3 - Prob. 6SBECh. 2.3 - Prob. 7SBECh. 2.3 - Solving Linear Equations In Exercises S-7 through...Ch. 2.3 - Prob. 9SBECh. 2.3 - Solving Linear Equations In Exercises S-7 through...Ch. 2.3 - Prob. 11SBECh. 2.3 - Solving Linear Equations In Exercises S-7 through...Ch. 2.3 - Prob. 13SBECh. 2.3 - Prob. 14SBECh. 2.3 - Prob. 15SBECh. 2.3 - Prob. 16SBECh. 2.3 - Prob. 17SBECh. 2.3 - Prob. 18SBECh. 2.3 - Prob. 19SBECh. 2.3 - Prob. 20SBECh. 2.3 - Prob. 21SBECh. 2.3 - Prob. 22SBECh. 2.3 - Prob. 23SBECh. 2.3 - Prob. 24SBECh. 2.3 - Prob. 25SBECh. 2.3 - Prob. 26SBECh. 2.3 - Prob. 27SBECh. 2.3 - Reversing Roles of Variables In Exercises S-17...Ch. 2.3 - Prob. 29SBECh. 2.3 - Prob. 30SBECh. 2.4 - The number N of deer expected to be present on the...Ch. 2.4 - Prob. 2TUCh. 2.4 - Doubling Time An investment grows according to the...Ch. 2.4 - You Win the Lottery Congratulations You have just...Ch. 2.4 - Prob. 3ECh. 2.4 - Your Childs Education You want to begin making...Ch. 2.4 - Engine Displacement The displacement for an...Ch. 2.4 - Altmans z-score Altmans z-score is a financial...Ch. 2.4 - Admiralty Coefficient The Admiralty Coefficent A...Ch. 2.4 - Properller Size An ideal diameter d, in feet, of a...Ch. 2.4 - A Population of Foxes A breeding group of foxes is...Ch. 2.4 - Profit The monthly profit P for a widget producer...Ch. 2.4 - Prob. 11ECh. 2.4 - The Skydiver Again When a skydiver jumps from an...Ch. 2.4 - Falling with a Parachute If an average-sized man...Ch. 2.4 - A Cup of Cofee The temperature C of a fresh cup of...Ch. 2.4 - Reaction Rates In a chemical reaction, the...Ch. 2.4 - Population Growth The growth G of a population of...Ch. 2.4 - Van der Waals Equation In Exercise 18 at the end...Ch. 2.4 - Radioactive Decay The half-life of a radioactive...Ch. 2.4 - Prob. 19ECh. 2.4 - Prob. 20ECh. 2.4 - Grazing Kangaroos The amount of vegetation eaten...Ch. 2.4 - Grazing Rabbits and Sheep This is a continuation...Ch. 2.4 - Prob. 23ECh. 2.4 - Hosting a Convention You are hosting a convention...Ch. 2.4 - Breaking Even The background for this exercise can...Ch. 2.4 - Prob. 26ECh. 2.4 - Water Flea F. E Smith has reported on population...Ch. 2.4 - Hollings Functional Response Curve The total...Ch. 2.4 - Radius of a Shock Wave An explosion produces a...Ch. 2.4 - Prob. 30ECh. 2.4 - Home Equity When you purchase a home by securing a...Ch. 2.4 - Prob. 1SBECh. 2.4 - Prob. 2SBECh. 2.4 - Setting Up Equations Each of Exercise S-1 through...Ch. 2.4 - Prob. 4SBECh. 2.4 - Prob. 5SBECh. 2.4 - The Crossing-Graphs Method In Exercise S-5 through...Ch. 2.4 - The Crossing-Graphs Method In Exercise S-5 through...Ch. 2.4 - Prob. 8SBECh. 2.4 - Prob. 9SBECh. 2.4 - The Crossing-Graphs Method In Exercise S-5 through...Ch. 2.4 - The Crossing-Graphs Method In Exercise S-5 through...Ch. 2.4 - Prob. 12SBECh. 2.4 - Prob. 13SBECh. 2.4 - The Crossing-Graphs Method In Exercise S-5 through...Ch. 2.4 - Prob. 15SBECh. 2.4 - Prob. 16SBECh. 2.4 - Prob. 17SBECh. 2.4 - Prob. 18SBECh. 2.4 - The Single-Graph Method In Exercises S-17 through...Ch. 2.4 - Prob. 20SBECh. 2.4 - Prob. 21SBECh. 2.4 - Prob. 22SBECh. 2.4 - Prob. 23SBECh. 2.4 - Prob. 24SBECh. 2.4 - Prob. 25SBECh. 2.4 - Prob. 26SBECh. 2.4 - The Single-Graph Method In Exercises S-17 through...Ch. 2.4 - Prob. 28SBECh. 2.5 - During what time period would the broker advise...Ch. 2.5 - Prob. 2TUCh. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Prob. 2ECh. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Prob. 5.2ECh. 2.5 - Prob. 6ECh. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Prob. 9ECh. 2.5 - Prob. 10ECh. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Prob. 12ECh. 2.5 - Prob. 13ECh. 2.5 - Prob. 14ECh. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Reminder Round all answers to two decimal places...Ch. 2.5 - Prob. 17ECh. 2.5 - Prob. 18ECh. 2.5 - Prob. 19ECh. 2.5 - Prob. 20ECh. 2.5 - Prob. 21ECh. 2.5 - Prob. 1SBECh. 2.5 - Prob. 2SBECh. 2.5 - Finding Inequalities Each of Exercises S-1 through...Ch. 2.5 - Prob. 4SBECh. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Prob. 6SBECh. 2.5 - Prob. 7SBECh. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Prob. 9SBECh. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Prob. 13SBECh. 2.5 - Prob. 14SBECh. 2.5 - Solving Inequalities Solve the inequalities in...Ch. 2.5 - Prob. 16SBECh. 2.5 - Prob. 17SBECh. 2.5 - Prob. 18SBECh. 2.5 - Prob. 19SBECh. 2.6 - TEST YOUR UNTERSTANDING FOR EXAMPLE 2.12 Replace...Ch. 2.6 - World Crude Oil Production In 1956, M.King Hubbert...Ch. 2.6 - Life Expectancy Versus Health Care Spending One...Ch. 2.6 - Builders Old Measurement The Builders Old...Ch. 2.6 - Drug Concentration When a drug is administered...Ch. 2.6 - The Cannon at a Different Angle Suppose a cannon...Ch. 2.6 - Profit The weekly profit P for a widget producer...Ch. 2.6 - Marine Fishery One class of models for population...Ch. 2.6 - Enclosing a field You have 16 miles of fence that...Ch. 2.6 - Forming a pen We want to form a rectangle pen of...Ch. 2.6 - Sales Growth In this exercise, we develop a model...Ch. 2.6 - Maximum Sales Growth This is a continuation of...Ch. 2.6 - An Aluminum Can The cost of making a can is...Ch. 2.6 - Prob. 13ECh. 2.6 - Cost for a Can This is a continuation of Exercises...Ch. 2.6 - Prob. 15ECh. 2.6 - Laying Phone Cable City A lies on the north bank...Ch. 2.6 - Prob. 17ECh. 2.6 - Prob. 18ECh. 2.6 - Prob. 19ECh. 2.6 - Spawner-Recruit Model In fish management it is...Ch. 2.6 - Rate of Growth The rate of growth G in the weight...Ch. 2.6 - Health Plan The manager of an employee health plan...Ch. 2.6 - Size of High Schools The farm population has...Ch. 2.6 - Prob. 24ECh. 2.6 - Water Flea F. E. Smith has studied population...Ch. 2.6 - Prob. 26ECh. 2.6 - Prob. 27ECh. 2.6 - Maximum and Minimum Values In Exercise S-1 through...Ch. 2.6 - Maximum and Minimum Values In Exercise S-1 through...Ch. 2.6 - Prob. 3SBECh. 2.6 - Prob. 4SBECh. 2.6 - Prob. 5SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 8SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 10SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 12SBECh. 2.6 - Prob. 13SBECh. 2.6 - Prob. 14SBECh. 2.6 - Prob. 15SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 17SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 20SBECh. 2.6 - Finding Maxima and Minima In Exercises S-5 through...Ch. 2.6 - Prob. 22SBECh. 2.6 - Prob. 23SBECh. 2.6 - Prob. 24SBECh. 2.6 - Prob. 25SBECh. 2.6 - Prob. 26SBECh. 2.6 - Endpoint Maximum Find the maximum value of...Ch. 2.6 - Maximum and Minimum Find the maximum and minimum...Ch. 2.CR - Finding a Minimum Suppose the function...Ch. 2.CR - Population of Foxes A breeding group of foxes is...Ch. 2.CR - Prob. 3CRCh. 2.CR - Water Jug If a completely full 5-gallon water jug...Ch. 2.CR - Maxima and Minima Find the maximum and minimum...Ch. 2.CR - George Reserve Population The number of deer on...Ch. 2.CR - Prob. 7CRCh. 2.CR - Forming a Pen We want to form a free-standing...Ch. 2.CR - The Crossing-Graphs Method Solve using the...Ch. 2.CR - Prob. 10CRCh. 2.CR - Prob. 11CRCh. 2.CR - Prob. 12CRCh. 2.CR - Linear Equations Solve for W:L=98.42+1.08W4.14A.Ch. 2.CR - Growth of North Sea Sole The length of North Sea...Ch. 2.CR - Minimum Find the minimum value of x2+20/(x+1) on...Ch. 2.CR - Prob. 16CRCh. 2.CR - Prob. 17CRCh. 2.CR - Temperature Conversions The three principal...Ch. 2.CR - Lidocaine Lidocaine is a drug used to treat...Ch. 2.CR - The Single-Graph Method Use the single-graph...Ch. 2.CR - Prob. 21CRCh. 2.FR1 - Prob. 1ECh. 2.FR1 - Prob. 2ECh. 2.FR1 - Prob. 3ECh. 2.FR1 - Prob. 4ECh. 2.FR1 - Prob. 5ECh. 2.FR1 - Prob. 6ECh. 2.FR1 - Prob. 7ECh. 2.FR1 - Prob. 8ECh. 2.FR1 - Prob. 9ECh. 2.FR1 - Prob. 10ECh. 2.FR1 - Prob. 11ECh. 2.FR1 - Prob. 12ECh. 2.FR1 - Prob. 13ECh. 2.FR1 - Prob. 14ECh. 2.FR1 - Prob. 15ECh. 2.FR2 - Prob. 1ECh. 2.FR2 - Prob. 2ECh. 2.FR2 - Prob. 3ECh. 2.FR2 - Prob. 4ECh. 2.FR2 - Prob. 5ECh. 2.FR2 - Prob. 6ECh. 2.FR2 - Prob. 7ECh. 2.FR2 - Prob. 8ECh. 2.FR2 - Prob. 9ECh. 2.FR2 - Prob. 10ECh. 2.FR2 - Prob. 11ECh. 2.FR2 - Prob. 12ECh. 2.FR2 - Prob. 13ECh. 2.FR2 - Prob. 14ECh. 2.FR2 - Prob. 15ECh. 2.FR3 - Locating the Vertex of a Parabola In Exercises 1...Ch. 2.FR3 - Prob. 2ECh. 2.FR3 - Prob. 3ECh. 2.FR3 - Prob. 4ECh. 2.FR3 - Prob. 5ECh. 2.FR3 - Prob. 6ECh. 2.FR3 - Applications Exercises 5 through 13 illustrate...Ch. 2.FR3 - Prob. 8ECh. 2.FR3 - Prob. 9ECh. 2.FR3 - Prob. 10ECh. 2.FR3 - Prob. 11ECh. 2.FR3 - Prob. 12ECh. 2.FR3 - Prob. 13E
Knowledge Booster
Background pattern image
Algebra
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, algebra and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Text book image
Linear Algebra: A Modern Introduction
Algebra
ISBN:9781285463247
Author:David Poole
Publisher:Cengage Learning
Text book image
College Algebra
Algebra
ISBN:9781938168383
Author:Jay Abramson
Publisher:OpenStax
Text book image
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Text book image
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage
Text book image
College Algebra
Algebra
ISBN:9781337282291
Author:Ron Larson
Publisher:Cengage Learning
Text book image
Functions and Change: A Modeling Approach to Coll...
Algebra
ISBN:9781337111348
Author:Bruce Crauder, Benny Evans, Alan Noell
Publisher:Cengage Learning
SEE MORE TEXTBOOKS
01 - What Is A Differential Equation in Calculus? Learn to Solve Ordinary Differential Equations.; Author: Math and Science;https://www.youtube.com/watch?v=K80YEHQpx9g;License: Standard YouTube License, CC-BY
Higher Order Differential Equation with constant coefficient (GATE) (Part 1) l GATE 2018; Author: GATE Lectures by Dishank;https://www.youtube.com/watch?v=ODxP7BbqAjA;License: Standard YouTube License, CC-BY
Solution of Differential Equations and Initial Value Problems; Author: Jefril Amboy;https://www.youtube.com/watch?v=Q68sk7XS-dc;License: Standard YouTube License, CC-BY