More on Modeling 1.2: Separation of Variables January 18, 2007 HW change: 1.2 #38 is not due this week. Bring your CD-ROM to class Tuesday.

Slides:



Advertisements
Similar presentations
“Teach A Level Maths” Vol. 2: A2 Core Modules
Advertisements

First Order Differential Equations From the OCR specification Candidates should be able to: a)formulate a simple statement involving a rate of change as.
Differential Equations Definition A differential equation is an equation involving derivatives of an unknown function and possibly the function itself.
Direct Variation Certain formulas occur so frequently in applied situations that they are given special names. Variation formulas show how one quantity.
Modeling Using Variation
Date: 2.2 Power Functions with Modeling Definition Power Function Any function that can be written in the form: is a power function. The constant a is.

Homework quiz Simplify Completely: Test Friday 3/2 Simplifying expressions –Exponent properties (4.1, 4.2) Know how to apply the specific properties.
1 6.3 Separation of Variables and the Logistic Equation Objective: Solve differential equations that can be solved by separation of variables.
1Chapter 2. 2 Example 3Chapter 2 4 EXAMPLE 5Chapter 2.
Variation. Direct Variation if there is some nonzero constant k such that k is called the constant of variation.
Translating Word Problems into Equations. Avoid the nervousness! Follow these steps: Read the problem carefully and figure out what it is asking you to.
9 Differential Equations. 9.1 Modeling with Differential Equations.
TODAY IN ALGEBRA…  Learning Goal: 7.2 You will solve systems of linear equations by Substitution  Independent Practice.
Bell Work: Find the values of all the unknowns: R T = R T T + T = 60 R = 3 R =
8.6 Solving Exponential and Logarithmic Equations
Block 5 Stochastic & Dynamic Systems Lesson 18 – Differential Equations - Methods and Models Charles Ebeling University of Dayton.
How do we solve linear inequalities? Do Now: What do you remember about solving quadratic inequalities?
Solving Compound Inequalities. Compound Inequality – two inequalities connected by and or or.
Bellwork Tuesday Bellwork Solutions
Variables on Both Sides. Visual 5x + 6 = 3x + 12.
Simplifying and Solving Medina.
Substitution Method: 1. Solve the following system of equations by substitution. Step 1 is already completed. Step 2:Substitute x+3 into 2 nd equation.
Objective : Solving systems of linear equations by graphing System of linear equation two or more linear equations How do I solve linear systems of equations?
Welcome to Differential Equations! Dr. Rachel Hall
January 19 Ms. Wu says … thanks for working hard! Now get to work! 1)Get out HW )Get started on the warm up quietly. 3)Grade HW )Retrieve manila.
First, a little review: Consider: then: or It doesn’t matter whether the constant was 3 or -5, since when we take the derivative the constant disappears.
Section 7.5: The Logistic Equation Practice HW from Stewart Textbook (not to hand in) p. 542 # 1-13 odd.
Goal: Solve and write absolute value equations in one variable Section 4-4: Solving Absolute Value Equations.
1.7 “Absolute Value” Absolute Value is always positive!! 7 = 7-7 = 7 **When solving equations or inequalities, you MUST set up 2 separate problems, one.
Price Elasticity of Demand. Definition Price elasticity of demand is an important concept in economics. It shows how demand for a product changes when.
1.4 Setting Up Equations; Applications. Verbal Description Language of Math Mathematical Problem Solution Real Problem.
Solving by Elimination Example 1: STEP 2: Look for opposite terms. STEP 1: Write both equations in Standard Form to line up like variables. STEP 5: Solve.
A cylindrical tank is initially filled with water to a depth of 16 feet. A valve in the bottom is opened and the water runs out. The depth, h, of the.
Quadratic Relations Solving Quadratic Equations Day 3: Solve by Factoring Tuesday, January 05, 20161Day 2 - Solve by Factoring.
Differential Equations Math meets the real world!.
SOLVING PERCENTAGE of CHANGE EQUATIONS PRE213 A dress costs $45 but there’s a 25% off sale. What’s the new price? Sometimes it helps to use a table to.
Warm Up Dec. 19 Write and solve the differential equation that models the verbal statement. Evaluate the solution at the specified value. The rate of change.
Differential Equations Linear Equations with Variable Coefficients.
Warm Up. Solving Differential Equations General and Particular solutions.
6.5: RELATED RATES OBJECTIVE: TO USE IMPLICIT DIFFERENTIATION TO RELATE THE RATES IN WHICH 2 THINGS ARE CHANGING, BOTH WITH RESPECT TO TIME.
Postman Stories for Multiplying Integers. What do you think? Should a check be represented by a positive number, or a negative one?
Solving a System of 3 Equations with 3 Unknowns. Breakdown Step 1 Labeling Step 2 Reduce to a 2 by 2 Step 3 Substitute Back In Step 4 Check Solution.
Write the equivalent equations and find out how many chocolates are in each box, represented by c. MSA 3.4b – Solving Equations with negative numbers Learning.
AP Calculus AB 6.3 Separation of Variables Objective: Recognize and solve differential equations by separation of variables. Use differential equations.
Test Taking Strategies 1.Mark a difficult problem and come back and do it later. 2.Circle, underline, or box the word NOT. 3.Eliminate answer choices that.
Section 9.4 – Solving Differential Equations Symbolically Separation of Variables.
Differential Equations
Pre-Algebra Unit 5 Review
Algebra Bell-work 9/13/17 Turn in your HW! 1.) 7x – 6 = 2x + 9
Chapter 9.3: Modeling with First-Order Differential Equations
Setting up and Solving Differential Equations
Solve a system of linear equation in two variables
Two-Step Equations Mrs. Book.
Solving Two-Step Equations
Do Now 1) t + 3 = – 2 2) 18 – 4v = 42.
Differential Equations
Rates that Change Based on another Rate Changing
2nd 9 Weeks MidPoint Review
SECTION 2-4 : SOLVING EQUATIONS WITH THE VARIABLE ON BOTH SIDES
Objectives Identify solutions of linear equations in two variables.
Solving Equations with Variables on Both Sides
Solving Equations with Variables on Both Sides
Objective Solve one-step equations in one variable by using addition or subtraction.
Warm-Up 1) Sketch a graph of two lines that will never intersect.
Objective Solve one-step equations in one variable by using addition or subtraction.
Section 6.2 Calculus AP/Dual, Revised ©2018
Which equation does the function {image} satisfy ?
Bell Work Write an equation for the following situation. And solve the problem. Jared wanted to know how much money to bring to the movies, he was bringing.
11-5 Solving Rational Equations
Presentation transcript:

More on Modeling 1.2: Separation of Variables January 18, 2007 HW change: 1.2 #38 is not due this week. Bring your CD-ROM to class Tuesday.

A mystery Here’s a new population model… Find the equilibrium solutions. For what values of P is the population increasing? decreasing? Sketch some solutions to the differential equation. Can you think of a situation in which this model makes sense? Be creative… From last time…

Spread of a rumor (group work) Quantities: (identify as indep var, dep var, or parameter) P = population of city N = people who have heard the rumor t = time k = proportionality constant Answers: 1.dN/dt 2.P - N 3.dN/dt = k(P - N) 4.dN/dt = k(350 - N) (N is in thousands, t could be days, weeks, etc. Your choice of units for t affects the value of k.) What should solutions look like? equilibrium solutions?

mmmm… Chocolate! Quantities: T = temp (degrees F) of hot chocolate at time t t = time in minutes, hours, etc. ( Why doesn’t it matter?) k = proportionality constant Equation: (Should k be positive or negative?)

HUH????? I asked you to look at the statement on p. 22: “So we should never be wrong.” What does that mean? Check this out: Paul says “y 1 (t) = 1 + t is a solution.” Glen says “y 2 (t) = 1 + 2t is a solution.” Bob says “y 3 (t) = 1 is a solution.” Who is right? How can we tell?

Separable Diffy-Q’s Example: Suppose the chocolate started out at 150 o and was 100 o 15 minutes later. How would you solve this initial value problem?