Math 10 Ch 7. Linear Equations and Graphs Lesson …...Math 10 Ch 7. Linear Equations and Graphs...
Transcript of Math 10 Ch 7. Linear Equations and Graphs Lesson …...Math 10 Ch 7. Linear Equations and Graphs...
Math 10 Ch 7. Linear Equations and Graphs Lesson 7-1 Lesson 7-1 Slope-Intercept Form Investigate: Graph the following lines using a table of values: (Hint: for part b you may find it easier to choose “x” values that are multiples of 3)
a) 2 3y x b) 2
53
y x
Things to think about:
1) Could you tell that the graph of 2 3y x would form a line before you started graphing it? How?
2) How could you tell if the point (-5, -7) is on the line represented by the equation 2 3y x ?
3) Which of the following points are on the line represented by the equation 2 3y x ?
(10, 23) (1.5, 5) (5, 12) (200, 403)
Use your graphs to complete the table:
Equation
Slope
y-intercept
2 3y x
25
3y x
What do you notice? ________________________________________________________________
y-intercept: - the y-coordinate where the graph of a
line or function crosses (intersects) the y axis.
- The value of y when x=0
Math 10 Ch 7. Linear Equations and Graphs Lesson 7-1 Ex. #1 Write the equation of each line in slope-intercept form. Ex. #2 Complete the table below:
Equation Slope y-intercept
5 2y x
35
7y x
3 5
57
71
33
2y x
The Equation of a Line (in slope-intercept form):
Math 10 Ch 7. Linear Equations and Graphs Lesson 7-1 Ex. #3 Graph each of the following lines without using a table of values. Check your work with a graphing calculator:
a) 2
13
y x b) 3 4y x
Ex. #4 Find the slope and y-intercept of the following lines:
a) 2 3 9x y b) 4 8 15 0x y
Ex. #5 a) Point C(-2,-6) is on the line 2y x b . Find the y-intercept of the line.
b) Point D(4,-5) is on the line 5y mx . Find the slope of the line.
Math 10 Ch 7. Linear Equations and Graphs Lesson 7-1 Ex. #6 Student Council decides to hold a dinner-dance. The cost to decorate the gym, rent the dishes and sound
equipment and to print the posters advertising the event is $475. Dinner costs $20 per person. a) Graph the cost of the event against the number of people who attend. The gym can hold a maximum of 400
people.
b) For your graph, identify the: independent variable ________________ dependent variable __________________ Domain ________________ Range _______________ Does this graph represent a function? _______ (how do you know?)
c) Write an equation to represent the cost of hosting the dance. Let C represent the total cost and n the number
of students who attend.
d) What does the slope represent? the y-intercept?