perpendicular lines have slopes that are the negative reciprocals of each others slopes. this means that you can:
1. write the slope as a fraction (if not already one),
2. flip the fraction over
3. multiply the fraction by - 1
4. And you have perpendicular lines slope.
so the slope of this line is - 1 so:
1. - 1 = - 1/1 convert to fraction
2. - 1/1 = - 1/1 flip but this case stays same
3. - 1/1 * - 1 = 1 multiply by - 1
4. slope is 1
we have slope and point so we can plug into equation:
y = mx + b
with m as slope and b is y intercept.
plug values:
4 = 1 * (- 2) + b
6 = b
so y intercept would be (0,6)
