All About Lines
By: Rebecca Ngo and Maggie McKenna
Equations of Lines
SLOPE INTERCEPT FORM
y=mx+b
ex: y=2x+5
-in this equation, the slope of the line would be 2 and the y-intercept would be 5
-the slope is I
STANDARD FORM
Ax+By=C
ex: 4x+6y=12
POINT-SLOPE FORM
y-y1=m(x-x1)
ex: y-3=4(x-12)
Main topic
Types of Lines
DIAGONAL LINE
-a diagonal line has the equation y=mx+b
-the slope doesn't equal zero
-ex: y=2x-4
VERTICAL
-a vertical line goes up and down
-the equation would be x=a
-the slope is undefined
-ex: x=2
PERPENDICULAR
-when two straight lines intersect each other at right angles
-have opposite reciprocal slopes
-ex:
line one: y=2/3x-12
line two: y=-3/2+4
PARALLEL
-when two lines never meet each other, no matter how long you extend them
-slopes are the same
-ex:
line one:y=2/3x-12
line two: y= 2/3x+4
HORIZONTAL
-a horizontal line runs from left to right
-the equation is y=b
-the slope is zero