Good catch from Amaston. Except each of the 3 first equations is the equation of a plane in a 3d-space (and not a line).
The intersection of 3 planes is a point (except if 2 or more are parallel, which is not the case here).



It can't, so you're stuck.

This post was edited by feanur on Sep 20 2015 09:45am

theres a solution that satisfies all 3. my professor alrdy posted the solutions and he is right as well

It can't satisfy all 4 equations because the inverse of A exists => unique solution => (0,0,0) is the *only* solution to the first 3 equations.

This post was edited by Amaston on Sep 20 2015 09:50am

Haha, yup, replace everywhere I said line with plane

ok and it doesnt satisfy the 4th equation. test out the numbers posted in the 1st page, and they check out

RzChaos is not right at all.
He gave you an approximate "solution", that is a triplet (x; y; z) for whom the first 3 calculations give approximately 0 and the last gives approximately 1.

I already gave you another approximate "solution", that is the triplet (0; 0; 0), for which the first 3 calculations give exactly 0, and the last gives approximately 1 :
0² + 0² + 0² = 0
and 0 is approximately 1.

Notice that the huge difference of scale among the coefficients (300.21 , 114.21 , ... and 1) makes this thing possible.

It's like saying : the point at the intersection of those 3 planes almost lies in the sphere (it's really close to it !).

It's *almost* a solution (they don't check out by errors on the order of 10^-2).

There are two *almost* solutions if we look graphically:



This post was edited by Amaston on Sep 20 2015 10:09am

The planes nearly come together on the upper right and lower left -- it's easier to see in MATLAB because you can rotate it, but you can probably see the upper right "almost" solution

If you've got matlab, put this in and play with the figure:

% setup the circle data
phi = linspace(0,pi,100)
theta = linspace(0,2*pi,100)
[phi,theta] = meshgrid(phi,theta)
Xs = sin(phi).*cos(theta)
Ys=sin(phi).*sin(theta)
Zs = cos(phi)

% draw the planes
[X,Y] = meshgrid(-5:1:5)
Z1 = (300.21*X-45*Y)/25
Z2 = (-45*X+40.21*Y)/(-65)
Z3 = (-25*X+65*Y)/(-114.21)
surf(X,Y,Z1)
hold on
surf(X,Y,Z2)
surf(X,Y,Z3)
plot3(Xs,Ys,Zs)
axis([-2,2,-2,2,-2,2])

This post was edited by Amaston on Sep 20 2015 10:04am

yea they are approximate solution cause he rounded it lol

but how can i solve this on matlab? can someone tell me the code for it