Graphing Lines Flashcards
What is a linear equation?
It is a straight line (not a curve), and the x is not squared or cubed.
What are the three forms of a line?
slope-intercept, point-slope, and standard form
What is the Point Slope Form?
y-y = m (x-x)
What is the Slope Intercept Form?
y=mx+b
What is the Standard Form?
Ax+By=C
y-y=m(x-x) is what form?
Point Slope
y=mx+b what form?
Slope Intercept
Ax+By=C What form?
Standard Form
Why is it called “point-slope” form?
It has a hidden point (x,y) and a slope (m) in it
Why is it called “slope-intercept” form?
It has a slope (m) and an intercept (b) in it
How do you find the hidden point in point slope form? y-y=m(x-x)
To get your (x,y), take the opposite of the number next to the x to get your x, and take the opposite of the number next to the y to get your y
How do you find the X-Intercept in Standard Form?
Use ( C over A, 0) to get the x intercept.
How do you find the slope in Standard Form?
m = -A/B (opposite of A over B)
How can you find the y intercept in any form?
You can always just plug a zero in for x and then solve for y. (0, __).
How can you find the x intercept in any form?
You can always just plug a zero in for y and then solve for x. (__ ,0)
What are the slopes of the diagonals of a square?
+1 and -1
A slope of 1/10 is closer to (zero or one)
zero
A slope of 7/8 is closer to (zero or one)
one
What do you call something that goes straight up and down?
VERTICAL
What do you call something that goes from left to right?
HORIZONTAL (like looking along the horizon)
If a line has a y intercept of 9, then the point _____ is on the line.
(0,9)
If a line has an x intercept of 9, then the point _____ is on the line.
(9,0)
the equation for the slope of the line is (if you have two points)
m = y-y / x-x
People think of the slope as _____ over _____
RISE, RUN
What is the name of the point (0,0) ?
origin
What is the equation of a perfect positive diagonal going through the origin?
y=x
WHat is the equation of a perfect negative diagonal going through the origin?
y=-x