 # 1-31-13 Unit 1 Basics of Geometry Linear Functions.

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Unit 1 Basics of Geometry Linear Functions

Review of Formulas Formula for Slope Standard Form
*where A>0 and A, B, C are integers Slope-intercept Form Point-Slope Form

Parallel and Perpendicular Lines
Write the equation of a line that passes through a given point, parallel to a given line. Write the equation of a line that passes through a given point, perpendicular to a given line.

Parallel lines Parallel lines have the same slopes. Lines in the same plane that do not intersect are called parallel lines. Parallel lines have the same slope.

Perpendicular Lines Lines that intersect at right angles are called perpendicular lines. The slopes of these lines are opposite reciprocals. Perpendicular lines have opposite reciprocal slopes. In order to find the slope of a line perpendicular to a given line, simply find the slope of the given line, take its reciprocal (flip it over) and make it the opposite sign .

neither parallel perpendicular
From the given equations, determine if the corresponding lines are parallel, perpendicular, or neither. y = 2x + 2 y = 4x - 2 neither 2x + 6y = 1 4x + 12y =3 parallel perpendicular

Example 1: Write the slope intercept form of an equation for the line that passes through (12,3), and is parallel to the graph of

Example 2: Write the slope intercept form of an equation for the line that passes through (1, -3), and is perpendicular to the graph of

Example 3: Write the slope intercept form of an equation for the line that passes through (-6, 5), and is perpendicular to the graph of x - y= 5