Find the equation for the line passing through the point (-4,-1) and perpendicular to the line whose equation is -1 x + 2y + 4=0.
Let's find the slope of the given line
-1 x + 2y + 4=0 add 1x to both sides subtract 4 from both sides
2y = 1x - 4 divide by 2
y = (1/2)x - 2 the slope = 1/2
And the slope of a perp. line will be the negative reciprocal of this = -2 / 1 = - 2
So we have
y = m ( x - x1) + y1 where m is the slope = - 2 and (x1, y1) = (-4,-1)
So we have
y = -2 (x - -4) + - 1
y = -2 (x + 4) - 1
y = -2x - 8 - 1
y = -2x - 9