precalc
posted by Anonymous .
I;m not sure if i am doing this right...I keep getting a negative intersection point, which doesn't seem possible.
Please help!
a) find the equatoin of line 1 which passes through (1,3) and (9,7)
I get y=3+1/2(x+1)or y=1/2x+2.5
b) the line 2 is perpedicular to line 1 and passes through 5,0. find the equation
for this one i get y=2x+10
c) find where line 1 and line 2 intersect each other. use this to compute the distance between the point (5,0) and line 1
I get (5,0) for the intersection, which doesnt make sense to me?
Thanks

line 1:
(y3)/(x1) = (73)/(91)
y3 = 1/2 (x1)
y = 1/2 x + 5/2
you are correct
line 2:
(y0) = 2 (x5)
y = 2x + 10
you are correct
1/2 x + 5/2 = 2x + 10
5/2 x = 15/2
x = 3 so y=4
The lines intersect at (3,4)
d^2 = (35)^2 + (40)^2
d^2 = 4+16 = 20
d = 2√5