The point where the medians of triangle meet

Complex numbers, rational functions, logarithms, sequences and series, matrix operations, etc.
honest_denverco09
Posts: 43
Joined: Tue Mar 31, 2009 2:06 am
Contact:

The point where the medians of triangle meet

Postby honest_denverco09 » Thu Apr 30, 2009 3:18 am

EX : A(8, -2) , B(1,5) and C(4, -5) are vertices of triangle ABC.
We knew the equations of the three medians of this triangle are y = -0.36x + 0.9 , y = -1.7x + 6.7 , y = 13x - 57
How can i locate the point where the medians meet ?

Thanks a lot! :wink:

User avatar
stapel_eliz
Posts: 1733
Joined: Mon Dec 08, 2008 4:22 pm
Contact:

Postby stapel_eliz » Thu Apr 30, 2009 11:32 am

honest_denverco09 wrote:...the equations of the three medians of this triangle are y = -0.36x + 0.9 , y = -1.7x + 6.7 , y = 13x - 57
How can i locate the point where the medians meet ?

The point of intersection of two lines is the solution to the system of equations created by the two lines' equations. So solve the system! :wink:

Note: Since the medians all meet at the same place, it doesn't matter which two of the three lines you pick for your system. You'll get the same answer, whatever your choice.

Also, since the three line equations are already solved for "y=", using "substitution" will probably be the simplest method of solution. For instance, if you pick the first two equations, you could "substitute" "-0.36x + 0.9" for "y" in the second equation, getting:

. . . . .-0.36x + 0.9 = -1.7x + 6.7

Then multiply through by 100 to get rid of the decimals:

. . . . .-36x + 90 = -170x + 670

. . . . .134x = 580

...etc, etc, and so forth. :D

The above assumes, of course, that the equations for the medians are correct. Upon checking, they do not appear to be. It might help if the original exercise and your work so far were posted.

honest_denverco09
Posts: 43
Joined: Tue Mar 31, 2009 2:06 am
Contact:

Re: The point where the medians of triangle meet

Postby honest_denverco09 » Fri May 01, 2009 12:04 am

Thank a lot, you guy! Thankful! :clap:


Return to “Advanced Algebra ("pre-calculus")”