Algebra Ii

Front 1

One of the most important properties of a straight line is in how it angles away from the horizontal.
y = ( 2/3 )x – 4.

Back 1

Slope

Front 2

The other format for straight-line equations.
* Find the equation of the straight line that has slope m = 4 and passes through the point (–1, –6).
y – y1 = m(x – x1)
y – (–6) = (4)(x – (–1))
y + 6 = 4(x + 1)
y + 6 = 4x + 4
y = 4x + 4 – 6

y = 4x – 2

Back 2

Point-Slope form

Front 3

The most useful form of straight-line equations. (y=mx+b)

* Find the equation of the straight line that has slope m = 4 and passes through the point (–1, –6).


y = mx + b
(–6) = (4)(–1) + b
–6 = –4 + b
–2 = b
y = 4x – 2

Back 3

Slope Intercept Form

Front 4

A line that has right angles to the horizon and is straight up and down. Slope is undefined.

x = 2.5

Back 4

Vertical Line

Front 5

A line that is straight across and a constructive line, either drawn or imagined, which passes through the point of sight, and is the chief line in the projection upon which all verticals are fixed, and upon which all vanishing points are found.

y=2.5

Back 5

Horizontal Line

Front 6

Algebra

Back 6

II