Question

Eliana claims she has discovered a method for determining the general form equation of a line

The line Ax + By + C = 0 will always be perpendicular to the line Bx - Ay + C = 0.
Is Eliana's method reasonable? Explain why or why not?

Answer 1

The answer is below

Explanation:

The general form of a line is given by:

Ax + By + C = 0

The slope intercept form of a line is give by:

y = mx + b;

where m is the slope and b is the y intercept

Given a line with equation Ax + By + C = 0; the slope of the line can be gotten by representing in slope intercept form, hence it becomes:

By = -Ax - C

y = (-A/B)x - C/B

The slope is -A/B

For a line with equation Bx - Ay + C = 0:

Ay = Bx + C

y = (B/A)x + C/A

the slope is B/A

Two lines are said to be perpendicular if the product of the slopes is -1. Hence:

-A/B * B/A = -1; hence the two lines are perpendicular