Post on 01-Sep-2014
description
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Slope and Formula
slope = Change in dependant variable Change in independant variable
m = Change in y Change in x
= y2 y1 x2 x1
= Δ y Δ x
Δ is a symbol that means "change in"
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From graph to formula
independent variable
slope
Dependent Variable
P = 6 hours + 30
constant
independent variable
slope
Dependent Variable
y = mx + b
constant
Standard form
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1. Using the freezing point and the boiling point of water, determine the slope of the line.
2. State the meaning of the slope value.
3. Write a formula to represent the relation between degrees on the Fahrenheit (F) scale and degrees on the Celsius (C) scale.
dependent variable = slope x independent variable + fixed value
Example 1
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Example 2
Company A charges a car rental fee of $20 a day and $0.15/kilometre. Company B charges a car rental fee of $30 a day and $0.10/kilometre.
1. State the independent and dependent variables of the relation.
2. Using the letters C for cost and d for the distanced traveled in kilometres, write the formula that represents Company A’s rental fee.
3. Using the letters C for cost and d for the distance traveled in kilometres, write the formula that represents Company B’s rental fee.
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Example 3
Company A charges a car rental fee of $20 a day and $0.15/kilometre. Company B charges a car rental fee of $30 a day and $0.10/kilometre.
Company A’s rental fee can be represented by the following formula: C = 0.15 n + 20
Company B’s rental fee can be represented by the following formula: C = 0.10 n + 30
1. Complete the table of values for each company using the appropriate formula.
2. Graph the data for Company A and Company B on the same grid.
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Assignment
p290
Questions 14
Answers page page 468