Transcript
Today:News & Notes
Warm-UpReview: Graphing Inequalities
Khan Academy Practice QuestionsIntroduce: parallel & Perpendicular Lines
News & Notes:
1. very nice work on Khan Academy this past week and weekend. I am sincerely impressed.
Day: total minutes: hours:
Thursday 829 13.82 Friday 1158 19.30Saturday 1154 19.223-day totals: 3141 52.35
2. Test this week (thurs. or Fri.) on graphing inequalities, parallel and perpendicular lines. what you do, (or don't do) everyday affects your grade. Be responsible, you'll feel good, really.
Warm-Up:
2. From the table, determine the function, fill in the missing values, and write the equation solving for y (y = )
1.
Warm-Up:3. From the table, determine the function, fill in the missing values, and write the equation solving for y (y = )
4.
(7x + 2) - (3x - 5)
4.
(3x + 2) (5x + 4) 5.
6.
Warm-Up:7. 6a²c² + 2ac² + 10ab²c3 Find the GCF: 8. Simplify:
9.
10.
a. What's wrong with this picture?
b. 40 ounces cost $5.20. What's the unit price?
Khan Academy Practice
Khan Academy Practice
Khan Academy Practice
Khan Academy Practice
Parallel & Perpendicular Lines
Two lines are
parallel
The lines never
intersect
Slopes are
equal
parallel lines have the same slopes so find the slope of the given line and the slope you want for a parallel line will be the same.
Perpendicular lines have negative reciprocal slopes. take the slope of the given line, switch the numerator and denominator and change the sign for the slope of its perpendicular line.
3
1m
3
1m
3
1m
31
3m
Parallel & Perpendicular Lines
(2, 4)
Let's find the equation of a line parallel to y = - x that passes through the point (2, 4)y = - x
What is the slope of the first line, y = - x ?
This is in slope intercept form so y = mx + b which means the slope is –1.
1
use the point-slope formula to find the equation of the line
Parallel & Perpendicular Lines
y -y1= -(x - x1) y -4 = -(x - 2)
y = -x + 6
(2, 4)
Let's find the equation of a line perpendicular to y = - x that passes thru the point (2, 4)y = - x
The slope of the first line is still –1.
The slope of a line perpendicular is the negative reciporical so take –1 and "flip" it over and make it negative.
1
1
1
1
So the slope of a perpendicular line is 1 and it passes through (2, 4).
Parallel & Perpendicular Lines
Parallel & Perpendicular Lines
Parallel & Perpendicular Lines
Class Work:
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