- #1
phoenix20_06
- 13
- 0
Homework Statement
Find the values of k such that lines 3kx+8y = 5 and 6y -4kx = -1 are perpendicular.
I don't need the answer, but a push in a right direction. However, feel free to solve the equation :)
Homework Equations
1. Slope of a line is m = [y2-y1]/[x2-x1] where we have 2 points on the line
P1(x1,y1) and P2(x2,y2)
2. Product of slope of 2 perpendicular lines is -1
let's say m1 is slope of line 1 and m2 is slope of line 2 then
m1 = -(1/m2)
The Attempt at a Solution
My attempts to resolve this equation are just confusing. I know that we have too many variables and we need to get rid of some of them.
I also know that at one point both equations are equal to each other (intersection point)
so...
3kx+8y = 5 and 6y -4kx = -1 are...
1. k = (5-8y)/3x and 2. k = (-1 -6y)/ -4x
if k = -(1/k) then
(5-8y)/3x = -((-4x)/(-1-6y))
(5-8y)(-1-6y) =(4x)*(3x)
-5 -30y +8y +48y^2 = 12x^2
and here I get stuck! What to do then? and am I taking a right path to solve this problem?
Thank you very much for any help!