slope of lines sec: 3-3 sol: g.2d zw&feature=related
TRANSCRIPT
http://www.youtube.com/watch?v=C1shoHMadzw&feature=related
Slope
Definition: denoted m, it is the vertical change (y the rise) over the horizontal change(x the run).
We use the first equation when given a graph, the second when given two points.
run
risem
12
12
xx
yym
Find the slope of the line passing through the points
(-4, -5)(6, -2)
Try these:1. (0, 3)(4, 8)2. (-5, 1)(5, -4)3. (-3, -2)(6, 1)
Parallel lines: Are two lines in a plane that do not intersect. Two lines are parallel IFF (if and only if) they have the same slope. m1=m2
Perpendicular lines: Two lines in a plane the intersect to form a right angle.Two lines are perpendicular IFF their slopes are negative reciprocals of each other.
or2
1
1
mm 121 mm
Ex:
• Given P(-2, 2), Q(2, 1), R(1, -1), and S(5, -2), determine if is parallel to or perpendicular to .
PQRS
Example
Graph the line that passes through the point (3, 5) that is perpendicular to TK with T(0, 2) and K(5, 0).
Rate of Change
Is a comparison of how much one quantity changes, on average, relative to the change in another quantity.
change Horizontal
change Verticalchange of Rate
0
1000
2000
60 120 180
(60,1000)
(180,0)
(0,2000)
18060
01000
Roc
3
18
120
1000
Roc
Because the line goes down it is descending 8(1/3) ft/sec