a Show that the linear system 2xy5 x2y2 xy3 is inconsistent
a) Show that the linear system:
2x-y=5
-x+2y=2
x+y=-3
is inconsistent.
b) Use the orthogonal projection of a vector on a subspace to find the best approximation of a solution of the linear system in a) (Show work)
c) Find a best approximation of the linear equation in a) using normal equations.
Solution
a) The System of equations have no solutions then they are called inconsistent
Given that 2x-y=5---->1
-x+2y=2--->2
x+y=-3---->3
from 1 and 2
2+3=> (-x+2y)+(x+y)=-1
=>3y=-1
=>y=-1/3
from 3-------->x+y=-3
x+(-1/3)=-3
=>x=-3+(1/3)=-8/3
So x= -8/3 and y = -1/3
Now, from 1, 2(-8/3)-(-1/3)=(-16/3)+(1/3)=-15/3=-5
from 2, -(-8/3)+2(-1/3)=8/3-(2/3)=6/3=2
from 3, -8/3+(-1/3)=-9/3=-3
therefore the system of equations have no solution.
therefore they are inconsistent.
