Solving 3 variables and 3 equations using matrices

F

frctl

Full Member
Joined
Jun 29, 2019
Messages
252
There is a method I am unfamiliar with to solving 3 variables and 3 equations using matrices.

matrix1.png
 
Well this does not make sense.
Give us something that make sense, like give us 3 equations and 3 variables and we solve the problem using matrices
 
The "augmented matrix" for the three equations in 3 unknowns:
ax+ by+ cz= d
ex+ fy+ gz= h
ix+ jy+ kz= l
is \begin{bmatrix}a & b & c & d \\ e & f & g & h \\ I & j & k & l\end{bmatrix}.

The matrix you have has too many columns.
 
Your new matrix (I need to post faster!) has the right number of columns but the last row is equivalent to the equation 0x+ 0y+ 0z= 1 which is impossible.
 
What about this matrix in the place:
 

Attachments

  • matrix1.png
    matrix1.png
    5 KB · Views: 12
Do you know how to make an inverse of a matrix? do you know how to multiply two matrices?
 
ok then this is too soon to go for it, it would be too much for just a forum discussion, it takes few sessions in the class to get through the whole thing
you can relax now
But now that you are interested you can still search for the courses about matrices and learn about it. you would be ahead of your time ;)
 
frctl said:
What about this matrix in the place:
matrix1-png.13429
Click to expand...
That matrix says exactly this (using x, y, z as the variables):

x = -3​
y = 0​
z = 7​

That is, it is already solved; this is your goal in using row operations, so all the work has been done except the interpretations.

By the way, as you've seen, "solving by matrices" can mean other things than what you are learning, so you should be careful how you describe it!
 
You must log in or register to reply here.
Top