2007-09-02 04:06:10 · 4 answers · asked by abraymond5 1 in Science & Mathematics ➔ Mathematics
m1 = (y + 4) / (4 - 2)
m1 = (y + 4) / 2
m2 = (- 2/13)
m1 x m2 = - 1
(- 2 /13 ) (y + 4) / 2 = - 1
y + 4 = 13
y = 9
2007-09-02 08:21:12 · answer #1 · answered by Como 7 · 2⤊ 1⤋
Hi,
The slope of a perpendicular line is the negative reciprocal of -2/13, which is 13/2. Substituting 13/2 for m and the x and y values of the 2 points into the slope formula of m = (y2 - y1)/(x2 - x1) gives:
13/2 = (y + 4)/(4 - 2)
Cross multiplying gives this equation to solve:
26 = 2y + 8
18 = 2y
9 = y
This slope would work out to (9-(-4))/(4 - 2) = 13/2
So y = 9 and the points are (2,-4) and (4,9)
I hope this helps!! :-)
2007-09-02 11:10:22 · answer #2 · answered by Pi R Squared 7 · 1⤊ 2⤋
m = (y - (-4)) /(4-2) = (y+4) /2 is the gradient through the points
and
-2/13 is the gradient of the line perpendicular
so
-2/13 = -1/m gives m = 13/2
so equating the two gives
(y+4) /2 = 13/2
y+4 = 13
y=9
the end
.
2007-09-02 11:10:12 · answer #3 · answered by The Wolf 6 · 2⤊ 2⤋
Mental math approach:
4-2 = 2
y-(-4) = 13 => y = 9
2007-09-02 11:14:00 · answer #4 · answered by sahsjing 7 · 2⤊ 2⤋