math problem for you math nerds out there

M

MrFuji

Veteran X
this problem was on my exam today, and it was the only one that i wasnt sure of the answer.

given that A, X, and D, are 4x4 matrices, and w is a scalar:

AX = wX + D

a)Which of the matrices in the equation must be invertible?(have an inverse)

b)solve the equation for X. (i solved this with just basic algebra, then i solved by taking inverses and still got the same answer)

for a, I put that X and A had to be invertible
for b, I got X = D/(A-w)

i dont feel like waiting a week to see the answer, so if someone could help a brotha out it'd be greatly appreciated.

and fuck all you haters that reply with gayness.
 
You can't subtract a scalar from a matrix.

There is no such thing as matrix division.

Multiplication is not commutative.

The answer should be:
X = (A - wI)^-1 * D
 
You must log in or register to reply here.
Back
Top