warm-up y = 2x + 2 make a t-table and graph the equation xy -2 0 2 1 6 4 2 0 -2
TRANSCRIPT
Warm-upy = 2x + 2 Make a T-Table and graph the equation
x y-2
-1
0
2
1
6
4
2
0
-2
Finding X and Y intercepts
What is an intercept?
Where the line crosses the x-axis.
y
x
5
5
-5-5
(0, 3)y-intercept = 3
(4, 0)x-intercept = 4
Where the line crosses the y-axis.
y
x
5
5
-5-5
(0, 3)
y-intercept = 3 (3, 0)
x-intercept = 3
In your notes:
1.)
y
x
5
5
-5-5
(0, -4)
y-intercept = -4 (-1, 0)
x-intercept = -1
In your notes:
2.)
X and Y Intercepts
Plug in 0 for y – this is the x-intercept
Plug in 0 for x – this is the y-intercept
Finding X intercepts
y
x
5
5
-5
-5
(5, 0)
x + y = 5x + (0) = 5
x = 5
x = 5
Finding X intercepts
y
x
5
5
-5
-5
(7, 0)
x - 3y = 7x - 3(0) = 7
x = 7
x = 7
Finding X intercepts
y
x
5
5
-5
-5
(6, 0)
6x + 12y = 366x + 12(0) = 36
6x = 36
x = 6
6 6
Finding Y intercepts
y
x
5
5
-5
-5
(0, -4)
y = -3x - 4y = -3(0) - 4
y = -4
y = -4
Finding Y intercepts
y
x
5
5
-5
-5
(0, 3)
-3x + 6y = 18-3(0) + 6y = 18
6y = 18
y = 3
6 6
Finding Y intercepts
y
x
5
5
-5
-5
(0, 6)y = ½ x + 6
y = ½ (0) + 6
y = 6
y = 6
Finding X and Y intercepts
y
x
5
5
-5
-5
(0, 2)
(3, 0)
2x + 3y = 62x + 3(0) = 6
2x = 6
2 2
x = 3
2x + 3y = 6
2(0) + 3y = 6
3y = 6
3 3
y = 2
Finding X and Y intercepts
y
x
5
5
-5
-5
(0, 2)
(4, 0)
4x + 8y = 164x + 8(0) = 16
4x = 16
4 4
x = 4
4x + 8y = 16
4(0) + 8y = 16
8y = 16
8 8
y = 2
Finding X and Y intercepts
y
x
5
5
-5
-5
(0, -2)
(4, 0)
x - 2y = 4x - 2(0) = 4
x = 4
x = 4
x - 2y = 4
(0) - 2y = 4
-2y = 4
-2 -2
y = -2
Finding x and y intercepts
Find the x-intercept of the line
X-intercept MEANS y = 0
- 3x + 2y = 9
Find the y-intercept of the line
y-intercept MEANS x = 0
Finding x and y intercepts
- 3x + 2y = 9
Cover up method
2x + 4y = 8 2x + 4y = 8
Solve for x and y.
Hint: Cover up the 4y first.
2x = 8
x = 4
Hint: Cover up the 2x this
time.
4y = 8
y = 2
y
x
5
5
-5-5
Use the Cover Up Method
- 6x – 4y = 2
-6x = 2
x = -1/3
-6x – 4y = 2
-4y = 2
y= -1/2
(-1/3, -1/2)
y
x
5
5
-5-5