Question
For each of the following, write the equation of the line determined by the given pair of points.?
(a) (3, -7) and (3, -27)
(b) (-4, 5) and (-8, -7)
(a) (3, -7) and (3, -27)
(b) (-4, 5) and (-8, -7)
Answers
Reiny
The first one is trivial since the slope is undefined, (notice delta x = 3-3 = 0, so we would be dividing by zero for the slope)
so the equation is x = 3
b) slope = (-7-5)/(-8+4) = -12/-4 = 3
so y = 3x + b
sub in (-4,5)
5 = 3(-4) + b
17 = b
equation: y = 3x + 17
so the equation is x = 3
b) slope = (-7-5)/(-8+4) = -12/-4 = 3
so y = 3x + b
sub in (-4,5)
5 = 3(-4) + b
17 = b
equation: y = 3x + 17