a.k.a. Proportion functions

Slides:



Advertisements
Similar presentations
A3 3.7 Direct and Indirect Variation
Advertisements

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.
3.4-1 Variation. Many natural (physical) phenomena exhibit variation = one quantity (quantities) changing on account of another (or several) Principle.
1 1.7 Direct and Inverse Variation The circumference of a circle is given by the formula C = 2  r, where r is the radius of the circle. The circumference.
Copyright © 2014, 2010, 2007 Pearson Education, Inc.
Variation Variation describes the relationship between two or more variables. Two variables, x and y, can vary directly or inversely. Three or more variables.
Table of Contents Direct and Inverse Variation Direct Variation When y = k x for a nonzero constant k, we say that: 1. y varies directly as x, or 2. y.
Direct Variation: y varies directly as x (y is directly proportional to x), if there is a nonzero constant k such th at 3.7 – Variation The number k is.
Variation and Proportion Indirect Proportion. The formula for indirect variation can be written as y=k/x where k is called the constant of variation.
Variation and Polynomial Equations
Proportions & Variation MATH 102 Contemporary Math S. Rook.
The general equation for DIRECT VARIATION is k is called the constant of variation. We will do an example together.
2.6 Scatter Diagrams. Scatter Diagrams A relation is a correspondence between two sets X is the independent variable Y is the dependent variable The purpose.
Direct Variation.
Direct and Inverse Variation
Direct and Inverse Variations Direct Variation When we talk about a direct variation, we are talking about a relationship where as x increases, y increases.
Copyright © Cengage Learning. All rights reserved. Graphs; Equations of Lines; Functions; Variation 3.
Combined variation functions - a function with more than one independent variable. Joint Variation - a type of combined variation where the independent.
Mathematical Modeling & Variation MATH Precalculus S. Rook.
Notes Over 4.5 Writing a Direct Variation Equation In Exercises 1-6, the variable x and y vary directly. Use the given values to write an equation that.
Direct & Inverse Variation
1 © 2010 Pearson Education, Inc. All rights reserved © 2010 Pearson Education, Inc. All rights reserved Chapter 3 Polynomial and Rational Functions.
Lesson 2.8, page 357 Modeling using Variation Objectives: To find equations of direct, inverse, and joint variation, and to solve applied problems involving.
Section 6Chapter 7. 1 Copyright © 2012, 2008, 2004 Pearson Education, Inc. Objectives Variation Write an equation expressing direct variation.
Direct and Inverse Variations Direct Variation When we talk about a direct variation, we are talking about a relationship where as x increases, y increases.
Certain situations exist where:  If one quantity increases, the other quantity also increases.  If one quantity increases, the other quantity decreases.
PROPORTION Given that y is proportional to x, find the missing values of y x y18.
Sullivan Algebra and Trigonometry: Section 2.5 Variation Objectives Construct a Model Using Direct Variation Construct a Model Using Inverse Variation.
HAWKES LEARNING SYSTEMS math courseware specialists Copyright © 2011 Hawkes Learning Systems. All rights reserved. Hawkes Learning Systems: Developmental.
Direct Variation  Let x and y denote two quantities. Then y varies directly with x, or y is directly proportional to x, if there is a nonzero number.
Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall.
Direct and Inverse.
2.7 Variation. Direct Variation Let x and y denote 2 quantities. Then y varies directly with x, or y is directly proportional to x, if there is a nonzero.
Lesson 6-9: Variation Objective: Students will: oFind the constant of variation and setup direct and inverse variation equations oUse variation equations.
2.4 and10.2 Direct/Inverse/Joint Variation ©2001 by R. Villar All Rights Reserved.
Find the surface area of a sphere
DIRECT and INDIRECT VARIATION ADV130 DIRECT VARIATION: A varies directly as B indicates a direct ratio where 2 things increase or decrease at the same.
k is called the constant of variation or constant of proportionality.
Unit 8: Day 1 Direct and Inverse Variation. Definition… Direct Variation: y varies directly as x This means as x increases, y __________ as x decreases,
KM & PP S 1 Direct & Inverse Variation. KM & PP 2 Variation y varies directly as x y = kx k is a constant The harder he hits, the higher it goes!
3.8 – Direct, Inverse, and Joint Variation. Direct Variation When two variables are related in such a way that the ratio of their values remains constant.
College Algebra K/DC Monday, 07 March 2016
Section 3.5 Mathematical Modeling Objective(s): To learn direct, inverse and joint variations. To learn how to apply the variation equations to find the.
Ratio and Proportions Percents Direct and Inverse Variation.
7.3 Ratio, Proportion, and Variation Part 2: Direct and Indirect Variation.
Notes Over 11.3 Using Direct and Inverse Variation When x is 4, y is 5. Find the equation that relates x and y in each case. Direct Variation Two quantities.
Copyright 2013, 2009, 2005, 2002 Pearson, Education, Inc.
The sales tax on an item varies directly with the cost of that item. The sales tax on a $24 shirt is $1.44. If the shirt is on sale for $19, what will.
how one quantity varies in relation to another quantity
Copyright © 2014, 2010, 2007 Pearson Education, Inc.
Direct and Inverse.
Copyright © 2014, 2010, 2007 Pearson Education, Inc.
Lesson 6-9: Variation Objective: Students will:
Chapter 7 Section 6.
Variation Objectives: Construct a Model using Direct Variation
Direct and Inverse.
4.7 Variation.
Rational Expressions and Functions
Rational Expressions and Functions
Direct and Inverse.
3.6 Direct and Inverse Variation
2.5 Model Direct Variation
VARIATION.
Direct and Inverse.
Direct and Inverse.
Direct and Inverse.
Direct Inverse and VARIATION.
Inverse.
Bell Work Combine all the like terms
Presentation transcript:

a.k.a. Proportion functions 3.6 Variation Functions a.k.a. Proportion functions

POD Simplify

POD Simplify

Direct variation General form: y = kx where k is the constant of proportionality Examples (what are the constants of proportionality?) C = 2πr A = πr2 (“A varies directly as the square of r.”) V = (4/3)πr3 (How would you say this?) The Dance

Indirect variation General form: y = k/x (where k is what?) Example: I = 110/R where I is current, R is resistance, and 110 is in volts. What is the constant of proportionality? The Dance

Another way to put it Direct variation functions resemble power functions of the form y = xn, where n > 0. y = 3x y = (¼)x2 y = x1/2 Inverse variation functions resemble power functions of the form y = xn, where n < 0. y = x-2 y = 6.3x-1/2 y = 4xn-3

Multiple variables Often, variation is a combination of more than two variables. In this case, there is still a constant of proportionality, and the different variables fall in a numerator or denominator. We’ll see this in two slides.

The method to find the equation Determine if the situation reflects direct or indirect variation. Write the general formula. Use given values to find k. Use k to write the specific formula. Use the specific formula to solve the problem.

Use it Write the specific formula for each of the following: 1. u is directly proportional to v. If v = 30, then u = 12. 2. r varies directly as s and inversely as t. If s = -2, and t = 4, then r = 7. 3. y is directly proportional to the square root of x, and inversely proportional to the cube of z. If x = 9, and z = 2, then y = 5.

Answer equations: 1. 2. 3.

Use it Hooke’s Law states that the force F required to stretch a spring x units beyond its natural length is directly proportional to x. A weight of four pounds stretches a certain spring from its natural length of 10 inches to a length of 10.3 inches. Find the specific formula. What weight will stretch this spring to a length of 11.5 inches?

Use it Hooke’s Law states that the force F required to stretch a spring x units beyond its natural length is directly proportional to x. A weight of four pounds stretches a certain spring from its natural length of 10 inches to a length of 10.3 inches. Find the specific formula. F = (40/3)x What weight will stretch this spring to a length of 11.5 inches? F = (40/3)(1.5) = 20 lbs.

Use it The electrical resistance R of a wire varies directly as its length l and inversely as the square of its diameter d. A wire 100 feet long, having a diameter of 0.01 inches has a resistance of 25 ohms. Find the specific formula. Find the resistance of a wire made of the same material that has a diameter of 0.015 inches and is 50 feet long.

Use it The electrical resistance R of a wire varies directly as its length l and inversely as the square of its diameter d. A wire 100 feet long, having a diameter of 0.01 inches has a resistance of 25 ohms. Find the specific formula. R = .000025l/(d2) Find the resistance of a wire made of the same material that has a diameter of 0.015 inches and is 50 feet long. R = 50/9 ohms

Use it Poiseuille’s Law states that the blood flow rate F (in L/min) through a major artery is directly proportional to the product of the fourth power of the radius and the blood pressure P. Express F in terms of P, r, and k. During heavy exercise, normal blood flow rates sometimes triple. If the radius of a major artery increases by 10%, approximately how much harder must the heart pump if the flow rate triples?

Use it Poiseuille’s Law states that the blood flow rate F (in L/min) through a major artery is directly proportional to the product of the fourth power of the radius and the blood pressure P. Express F in terms of P, r, and k. F = kPr4 During heavy exercise, normal blood flow rates sometimes triple. If the radius of a major artery increases by 10%, approximately how much harder must the heart pump if the flow rate triples? About 2.05 times as much.