1.4 Linear Equations in Two Variables Flashcards
measures steepness of a line
slope
the ratio of the rise to the run
slope
the change in the y-coordinates
rise
the change in the x-coordinates
run
symbol for the change in the x values (difference)
symbol for the change in the y values (difference)
slope formula
Other formulas for slope
Point-slope formula of a line
Slope-intercept formula of a line
Graph a line with positive slope
Graph a line with negative slope
Graph a line with zero slope
Graph a line with undefined slope
Standard form of a line
What do you know about the slopes of two nonvertical lines in a coordinate plane that are parallel
the slopes are equal
What do you know about the slopes of two perpendicular lines
the slopes are opposite reciprocals and
When asked to write an equation of a line, which form should you use?
point-slope
What is the equation of a vertical line?
What do you need to remember about standard form of a line?
Ax is first
By is second
C is on the opposite side of Ax and By
No fractions
No decimals
A should be positive
What is the equation of a horizontal line?
What is the slope of a vertical line?
undefined
What is the slope of a horizontal line?
0
When the slopes get larger in size, what do you know about the line?
the line becomes steeper
a line that rise from left to right
positive sloped lines
a line that falls from left to right
negative sloped lines
How do you write an equation of a parallel line?
Find the slope of the first line.
Use point-slope to plug in the slope and the point of the new line.
How do you write an equation of a perpendicular line?
Find the slope of the first line.
Take the opposite reciprocal of the slope found.
Use point-slope to plug in the slope and the point of the new line.
In the equation y = mx + b, what do m and b stand for?
m = slope
b = y-intercept
How do you write a y-intercept?
(0, y)
How do you write an x-intercept?
(x, 0)
