Monday, 2/8/10 SWBAT…write and graph parallel and perpendicular lines Agenda Parallel and perpendicular line practice with tablets Exit slip Warm-Up: Grab a tablet, eraser and dry erase marker Turn in any missing homework Turn in take-home tests HW: 1.) Do problems on back of agenda (review) 2.) Read and do the Graphing/ Substitution/ Elimination examples 1

Graph y = 3 and y = 7 on your tablet Are these two lines parallel, perpendicular or neither? Answer: Parallel

Graph x = 4 and x = 7 on your tablet Are these two lines parallel, perpendicular or neither? Answer: Parallel

y = -5/2x + 10 -5x + 2y = 20 Are these two lines parallel, perpendicular or neither? Answer: Neither

Question from hw said… Write an equation in slope-intercept form (y = mx + b) for the line that is PARALLEL to the given line and that passes through the given point. Graph BOTH LINES. Problem #6: y = -3/4x + 4 (-2, 3)

Graph y = -3/4x + 4 Find the equation of the line that is parallel to y = -3/4x + 4 that passes through (-2, 3) (Show work on the back of tablet) Graph y = -3/4x + 3/2 Do you see that both lines are parallel? (FYI: since slope is negative, line should fall when viewed from left to right)

Question from hw said… Write an equation in slope-intercept form (y = mx + b) for the line that is PERPENDICULAR to the given line and that passes through the given point. Graph BOTH LINES. Problem #14. y = -½ x (-2, 0)

Graph y = -1/2 x Find the equation of the line that is perpendicular to y = -1/2x that passes through (-2, 0) (Show work on the back of tablet) Graph y = 2x + 4 Do you see that both lines are perpendicular? (you should!)

OPEN ENDED Graph a line that is parallel and a line that is perpendicular to y = 2x – 1.

CHALLENGE If the line through (-2, 4) and (5, d) is parallel to the graph of y = 3x + 4, what is the value of d?

REASONING Is a horizontal line perpendicular to a vertical line sometimes, always, or never? Explain your reasoning.