Help please.?

Question

L is the line 2x-y+6=0

1/ the line K contains the point (-1,4) and is perpendicular to L.
find the equation of K.

2/find the co-ordinates of the point of intersection of L and K.

please explain how u did it and ty in advance.

Answer 1

get some graph paper out
draw the line 2x +y + 6 = 0

find the point x=-1 and y=4

draw a line from that point to the line L so that they meet at right angles, 90 deg

then you can work out the line equaltion by seeing where it cuts the X axis (horizontal) and where it cuts the Y axis (the vertical axis)
Good luck

Answer 2

The line perpendicular to L has equation x+2*y+c=0, since
2*(1)-1*(2)=0 the direction vectors are perpendicular. Now plug in -1 and 4 for x and y and get the value of c.

Answer 3

well L is y=2x+6
then you know that a perpendicular line will have and inversed and opposite sign variation coefficient (dunno what it is in english cuz im french)

so ur new equation will have -1/2x in it.
you also are given a point on this line
so put the coordonates in the equation to find b
4=-1/2 * -1 + B
find b to get the equation of K

to get the intersection you do K=L
so if L=x+2 and K=2x-4
you will do x+2=2x-4 then find x (those arent the real equations because i didnt calculate the real answers youll have to do that)

Answer 4

slope of line L = 2
slope of K is -1/2
eq of K y = -1/2x + b
sub(-1,4) 4 = 1/2 + b => b= 7/2
y = -1/2x + 7/2

Solve both eq to find the intersection of L and K
2x - y = -6
1/2x + y = 7/2
5/2x = -5/2
x = -1
y= 2x + 6 = 4
point = (-1,4)

Answer 5

Good luck dude! lo0l

Answer 6

click on the link below:

http://www.themathpage.com/aPreCalc/equation-of-a-line.htm

hope that helps...