Find the EQUATION of the LINE USING ANY ONE METHOD.
1. Look for a pattern
2. Graph it and get slope and y intercept
3. Use y = mx +b
4. Use pt slope formula
Oct 4­8:42 AM
10/5
GET READY FOR YOUR QUIZ. Turn in HW to box. Oct 4­8:56 AM
1
Oct 4­4:29 PM
10/5
Ex 2 Write the equation of the line through (2, ­3) and (4, 3)
Way 2
Way 1
y=m x+b
y­y1 = m (x­x1)
Pt. slope form
of equation
of line
Use either pt
Oct 3­8:29 AM
2
Graphing a line
Plotting Pts
Steps
1. Get y alone.
2. Plot any two pts.
Can you choose?
y = mx+b
Steps
1. Get y alone
2. First plot ___
3. Then, from __
x and y intercepts method
Steps
1. Easiest in standard form
2. X­ intercept: (____,____)
3. Y­intercept: get (____,____)
Oct 4­7:52 AM
1. Graph the line 4x + 2y = 12. SHOW TWO DIFFERENT WAYS.
Oct 5­8:14 AM
3
Graph
Oct 5­8:31 AM
Graph 5x ­ 2y = 10. Choose the easiest method. Oct 5­8:37 AM
4
1) Find the equation of the line for (15,13) and (2,­5)
Oct 5­7:37 AM
1) Find the equation of the line for (15,13) and (2,­5)
Oct 5­7:37 AM
5
10/8
Why is a vertical slope undefined? Use the points below to demonstrate.
Why is a horizontal slope zero?
how hard it is to walk up something
SLOPE
Oct 5­7:41 AM
10/8
Why is a vertical slope undefined? Use the points below to demonstrate.
Why is a horizontal slope zero?
how hard it is to walk up something
SLOPE
Oct 5­7:41 AM
6
10/8
Why is a vertical slope undefined? Use the points below to demonstrate.
Why is a horizontal slope zero?
how hard it is to walk up something
SLOPE
Oct 5­7:41 AM
10/8
Ex 2 Graph the line given that the y intercept is at(0,4) and the slope is ­2/3
Write the equation of the line for this information.
Ex 3 Graph me quickly. 5x ­4y = 20
Ex 4 Graph me quickly
5x ­4x = 20
Oct 5­7:39 AM
7
10/8
Ex 2 Graph the line given that the y intercept is at(0,4) and the slope is ­2/3
Write the equation of the line for this information.
Ex 3 Graph me quickly. 5x ­4y = 20
Ex 4 Graph me quickly
5x ­4x = 20
Oct 5­7:39 AM
3. Find equation of line through these points. Try more than one way.
(10,­3) and (19,­12)
Oct 5­7:37 AM
8
3. Find equation of line through these points. Try more than one way.
(10,­3) and (19,­12)
Oct 5­7:37 AM
Find the equation of the line through (4,5) with slope of 3/2
Oct 8­8:43 AM
9
Find the equation of the line through (4,5) with slope of 3/2
Oct 8­8:43 AM
3. The tibia is a bone in the human body that connects
the knee and the ankle. A man with a tibia 38.5 cm long should be about 173 cm tall and a man with a tibia 44.125 cm long should be about 188 cm tall.
a.
Write a linear equation with height, y, as a function of the length of the tibia, x.
b.
About how tall should a man be whose tibia is 40 cm long?
Oct 5­7:38 AM
10
Oct 8­8:42 AM
11