# equation of the line AB

• Sep 16th 2011, 06:05 AM
andyboy179
equation of the line AB
hi,

i need to find the equation of the line AB from A(2,0) B(3,1)

for this would i do:

AB=(square root) 1^2 + 1^2= (square root)2?

is this correct? if not where am i going wrong?
• Sep 16th 2011, 06:10 AM
Traveller
Re: equation of the line AB
The equation of a line refers to an equation in x and y which all points on that line satisfy. You have tried to find out the length of the line-segment AB which is not required. The following link should help.

Linear equation - Wikipedia, the free encyclopedia
• Sep 16th 2011, 06:19 AM
andyboy179
Re: equation of the line AB
thanks!

so would i do:
0=2m+c
1=3m+c

-1=-1

m=1
1=3+c 1/3=0.3
c=0.3

Y=1x+0.3???
• Sep 16th 2011, 06:27 AM
andyboy179
Re: equation of the line AB
would that be correct?
• Sep 16th 2011, 06:34 AM
Traveller
Re: equation of the line AB
Quote:

Originally Posted by andyboy179
thanks!

so would i do:
0=2m+c
1=3m+c

-1=-1

m=1

1=3+c

Correct.

Quote:

1/3=0.3
c=0.3

Y=1x+0.3???
There is a slight error in this. How do you solve 1 = 3 + c ?
• Sep 16th 2011, 06:35 AM
andyboy179
Re: equation of the line AB
i did, 1/3=0.3
• Sep 16th 2011, 06:38 AM
Traveller
Re: equation of the line AB
That is not how it is done. In an equation you perform the same operation on both sides. For example you can subtract some quantity, or divide both sides by a non-zero number. Which of the above would you do to get only c in a single side of 1 = 3 + c ?
• Sep 16th 2011, 06:39 AM
andyboy179
Re: equation of the line AB
could i -1 from both sides to make c=2?
• Sep 16th 2011, 06:44 AM
Traveller
Re: equation of the line AB
That way you will get 0 = 2 + c. What is the next step?
• Sep 16th 2011, 06:45 AM
andyboy179
Re: equation of the line AB
-2 from each side so c=-2 and the final answer would be y=1x-2???
• Sep 16th 2011, 06:56 AM
Traveller
Re: equation of the line AB
Quote:

Originally Posted by andyboy179
-2 from each side so c=-2 and the final answer would be y=1x-2???

Absolutely !
• Sep 16th 2011, 06:57 AM
andyboy179
Re: equation of the line AB
thanks alot mate!!