Question

https://gyazo.com/f4b5386358a6510a10b219672a2f0cd0

a) I found their slopes and they were perpendicular.
b) 3x+2y-11=0
c) r = (5,-2)+t(2,3)

Did I do it correctly?

Answer 1

I'm a little rusty on this but I believe to find the line with vector d1 passing through (5,-2) you would apply the vector to point (5,-2) and find the equation between (5+2,-2+3) and (5,-2) which is slightly different to yours

I believe a and c are good though

Answer 2

@angle sorry to bother but could you double check me?

Answer 3

I think, in terms of turning in an answer, you can add specific numbers for (a) because the question asks to "Show"
so you say something like: d1 has a slope of _____ and d2 has a slope of ____ and since they are flipped opposites of each other, this means the vectors are perpendicular.

Answer 4

Yeah, I gave an explanation for that.

Answer 5

For b tho:
I had direction vector: (2,3) and point (5,-2)
2x+3y+C = 0
2(5)+3(-2)+C = 0
C = -4
2x+3y-4=0
I think that's the right answer. Am I correct?

Answer 6

So that would change my answer for C as well

Answer 7

so this line has a slope = 3/2
and goes through points (5, -2) and (7, 1)

Answer 8

I think it's becomes a different equation than the one you came up with

Answer 9

But I don't see how I can be wrong. :\

Answer 10

I'm not sure what formula you're using, but I can try to show you in "point slope form"

y = m(x - h) + k
where m = slope and (h, k) a point in the line

y = (3/2)(x - 5) - 2 [plugged in values]
2y = 3(x - 5) - 4 [multiplied everything by 2]
2y = 3x - 15 - 4 [distributed the 3]
2y = 3x - 19 [added like terms]
3x - 2y - 19 = 0 [subtracted 2y from both sides]


so
3x - 2y - 19 = 0

Answer 11

so you were off by a just little in your first attempt :)

Answer 12

Okay, so I was trying with slope intercept form and I got this:

y=3/2x+b 

-2=3/2(5)+b 

b = -2-3/2(5) 

b = -19/2 

y=3/2x-19/2 ==> Multiply each side by 2 

2y = 3x-19 

2y-3x+19 = 0 

I don't get what I did wrong. 

Answer 13

it right
you can multiply through by -1 to get the same answer that I just got :)

Answer 14

Aha I see. So both equations can work. Tysm!!

Answer 15

mhm ^_^