Question

The director of a marching band uses a coordinate plane to design the band’s formations. During one formation, a drummer marches from point A to point B and then turns 90° to her right and marches until she reaches the x-axis.

a. When the drummer marches from point B to the x-axis, what is the equation of the line that she marches along?

Answer 1

When the drummer marches from point B to the x-axis, she is moving vertically downwards. In the coordinate plane, this means that she is decreasing the y-coordinate while keeping the x-coordinate constant.

Since she turns 90° to her right, her x-coordinate remains the same, but her y-coordinate becomes 0 when she reaches the x-axis.

Therefore, the equation of the line that she marches along is x = [the x-coordinate of point B].