\(\begin{array}{cl}{\text { Consider these four equations. }} & {} \\ {\text {
i. } y=2 x-3} & {\text { i. } y=-\frac{1}{2} x-6} \\ {\text { iii. }
y=\frac{2}{5} x+4} & {\text { iv. } y=-\frac{5}{2} x}\end{array}\)
$$\begin{array}{l}{\text { a. Graph the four equations on one set of axes. Use
the same scale }} \\ {\text { for each axis. Label the lines with the
appropriate roman numerals. }} \\ {\text { b. What is the slope of each line?
}} \\ {\text { c. What do you notice about the angle of intersection between
}} \\ {\text { Lines i and ii? Between Lines iii and iv? }} \\ {\text { d.
What is the relationship between the slopes of Lines i and i: }} \\ {\text {
Between the slopes of Lines iii and iv? }}\end{array}$$
$$\begin{array}{l}{\text { e. Make a conjecture about the slopes of
perpendicular lines. }} \\ {\text { f. Create two more lines with slopes that
fit your conjecture. Are }} \\ {\text { they perpendicular? }} \\ {\text {
9. Write an equation for the line that passes through the point }(-1,4)} \\\
{\text { and is perpendicular to } y=\frac{1}{3} x+4 . \text { Check your
answer by graph- }} \\ {\text { ing both lines on one set of axes. Use the
same scale for each axis. }}\end{array}$$