1- Suppose m1 and m2 are slopes of two parallel lines. What is the relationship between m1 and m2?

2- Suppose m1 and m2 are slopes of two perpendicular lines. What is the relationship between m1 and m2?

3- Write point-slope formulafor an equation of a line. What is coordinate of the point and what is the slope in this formula.

4- Suppose a line parallel to x axis goes through the point (a, b), what is the equation of this horizontal line?

5- Suppose a line parallel to y axis goes through the point (a, b), what is the equation of this vertical line?