November 20, 2013 Day 4 – Writing Equations of Parallel and Perpendicular Lines REVIEW Slope of Parallel Lines In a coordinate plane, two nonvertical lines are ________________ if and only if they have the ___________ slope. Decide whether the two lines are parallel. f(x) = 4x - 9 g(x) = 4x + 3 f(x) = -3/4x - 9 g(x) = 3/4x + 3 Slope of perpendicular lines Two nonvertical lines are ______________________ if and only if the product of their slopes is 1. Or we can say that the slopes are _______________ and __________________ of each other Decide whether the two lines are perpendicular. y = 3x + 5 y = 1/3x + 5 y = -9x + 4 y = 1/9x + 2 Decide whether the lines with the given equations are parallel, perpendicular, or neither. Because parallel lines have the ___________ slope and perpendicular lines have ______________ and __________________ slope, we can use that relationship to write the equations of lines that will be parallel and perpendicular to a given line.
Transcript
November 20, 2013
Day 4 – Writing Equations of Parallel and Perpendicular Lines
REVIEW
Slope of Parallel Lines
In a coordinate plane, two nonvertical lines are ________________ if and only
if they have the ___________ slope.
Decide whether the two lines are parallel.
f(x) = 4x - 9g(x) = 4x + 3
f(x) = -3/4x - 9g(x) = 3/4x + 3
Slope of perpendicular lines
Two non-‐vertical lines are ______________________ if and only if the product of their slopes is -‐1.
Or we can say that the slopes are _______________ and __________________ of each other
Decide whether the two lines are perpendicular.
y = 3x + 5y = 1/3x + 5
y = -9x + 4y = 1/9x + 2
Decide whether the lines with the given equations are parallel, perpendicular, or neither.
Because parallel lines have the ___________ slope and perpendicular lines
have ______________ and __________________ slope, we
can use that relationship to write the equations of
lines that will be parallel and perpendicular to a
given line.
November 20, 2013
Determine the slope of a line that has the following condition:
a. Parallel to the line b. Perpendicular to the line
c. Parallel to the line d. Perpendicular to the line
e. Parallel to the line y = 7 f. Perpendicular to the line x = 2
To write an equation that is parallel or perpendicular to a given line we need to:
1. Determine the ____________ our line will need to have to be parallel or perpendicular to the given line.
2. Use the determined slope and the ____________ to put the line in one of the forms of lines, slope-‐intercept, point-‐slope or standard.
Using the point given and the following information write the equations in slope intercept, point-‐slope and standard form.
a. (-‐3, 9) Parallel to b. (2, 5) Perpendicular to
