Question

Consider two lines L1: 6x-8y=5 and L2: y=3x/4 -5. A(3/2,1/2) is a point on L1.
(a) Show that L1//L2. [Done]
(b) If L3 is a straight line passing through A and perpendicular to L1, find the equation of L3.
(c) Find the point of intersection of L2 and L3.

Answer 1

could you find slope of L1?

Answer 2

3/4?

Answer 3

yes.

Answer 4

now, the slope of line perpendicular to line with slope m is -1/m
so whats the slope of line L3 ?

Answer 5

(3/4)*L3=-1
slope of L3=-4/3

Answer 6

correct, now u have both slope and a point, can u find equation ?
y-y1 = m(x-x1)

Answer 7

y-(3/2)=(-4/3)*(x-1/2) ?

Answer 8

yup, simplif it.

Answer 9

8x+6y-13=0?

Answer 10

yes, thats is correct.

Answer 11

wait

Answer 12

to find point of intersection, just solve the 2 equations of line simulatneously...

Answer 13

I think I have some steps calculate wrongly.....the answer is 8x+6y-15=0

Answer 14

let me check again...

Answer 15

u interchanged x1 and y1

Answer 16

y-(1/2)=(-4/3)*(x-3/2)

Answer 17

Oh yes....!!! wait a moment, let me change it

Answer 18

got it....
continue please.

Answer 19

to find point of intersection, just solve the 2 equations of line simultaneously...
can u ?

Answer 20

y=3x/4 -5
and
8x+6y-15=0
solve simultaneously.

Answer 21

please wait

Answer 22

x=6/5
y=-41/10

why so strange...

Answer 23

i got, 18/5 and -23/10 .....

Answer 24

well.....wait..

Answer 25

yes, I calculate wrongly. you are correct.

Answer 26

good, any more doubts ?

Answer 27

no more about this question.
thank you very much. :)

Answer 28

welcome ^_^