Let's begin by listing out the information given to us:
Line m is perpendicular to line P
Line P: (x, y) = (-4, -1), (1, 1)
We will proceed to calculate for the slope of the line P (as shown below):
Slope (m) = Δy/Δx
Slope (m) = (1 - - 1)/(1 - - 4) = 2/5
Slope (m) = 2/5
The slope of a parallel line is the negative reciprocal of the slope of the line.
Line m: slope (m) = -1/(2/5) = -5/2
Line m: slope (m) = -5/2
We calculate for the equation of the line using the point-slope equation. We have
y - y1 = m(x - x1) ⇒
(x1, y1) = (1, 1)
y - 1 = 2/5 (x - 1) ⇒ y - 1 = 2/5x - 2/5
y = 2/5x - 2/5 + 1
y = 2/5x + 3/5
We will proceed to put the value of the new slope into the equation. We have:
y = -5/2x + b ; (x, y) = (1, 1) ⇒ 1 = -5/2(1) + b
⇒ b = 5/2
Substitute the value of b into the point-slope equation, and we obtain the equation of line m. We have:
y = -5/2x + 5/2