170 likes | 371 Views
TYPES OF RELATIONS. LINEAR RELATIONS:. the graph is a straight line the rate of change “a” is constant (the rate of change between any 2 points on the line will be the same). RELATION 1 – CONSTANT FUNCTION.
E N D
LINEAR RELATIONS: • the graph is a straight line • the rate of change “a” is constant (the rate of change between any 2 points on the line will be the same)
RELATION 1 – CONSTANT FUNCTION • Consider the amount of fuel purchased and the price per litre. (Gas is 98.9 cents per litre) • Table of Values
RELATION 1 • Consider the amount of fuel purchased and the price per litre. (Gas is 98.9 cents per litre) • Table of Values
GRAPH ..straight line parallel to x-axis Price of Fuel Price per Litre (¢) 100 75 50 25 Amount (L) 0 5 10 15
RULE • The rule is: cost per litre = 98.9 ¢ • The rule is y = 98.9 ¢ Table of Values No matter what the x value is..the y value always stays the SAME
The cost per litre is constant • The rate of change is zero (a = 0) • We call this a ZERO VARIATION relation • The rule is: y = b (constant value) • y = 98.9
Do..Workbook page 107-108 Activity 2 Cost of Bus Ridedo..a,b,c,d,e,fpage 116 #8page 143 #2Textbook #1page 153 #4bring textbook #2 from now on
RELATION 2 – DIRECT VARIATION • The cost of apples is $2.50 per kg. • Independent variable: number of kg you buy • Dependent variable: cost of buying apples
RELATION 2 – DIRECT VARIATION • The cost of apples is $2.50 per kg. • Independent variable: # of kg of apples • Dependent variable: cost ($)
TABLE OF VALUES • Cost = 2.50 times the amount of kg purchased • y = 2.50 x depr.o.cindep Rule for direct y = a x Rule for this question: y=2.50x RULE
GRAPH Cost of Apples Cost ($) 10.00 7.50 5.00 2.50 Amount (kg) 0 1 2 3
DIRECT VARIATION • There is no initial fee (start-up cost) • Values are proportional (you can cross multiply and always get the same answer) • The rule is y = ax (“a” is the rate of change) y is depvar, x is indep. var • The graph is a straight line that passes through the origin
Work on zero and direct relations • Workbook Page 116 #8,9
Quiz on rate of change…take out a piece of paper..put your name on it… • Calculate the rate of change…write coordinates, label, write the formula, solve for the r.o.c 1- (2,10) (6,30) a =5 2- (-2,4) (5,-2) a= -6/7 3.- ( 1,8) (8,8) a= o 4- (26,12) (102,50) a= 38/76 or 1/2 5- (24,4) (12,8) a= -4/12 or -1/3