Question

find the inverse of [ 1 2-1]
[-4-7 3]
[-2-6 4]

Answer 1

How do they want you to do this?

Answer 2

I agree with mathteacher... do you have to do it by hand or can you use a TI-83 or excel or some other aid?

Answer 3

by hand

Answer 4

Do they want you to use cramer's method or do they want you to row reduce your matrix with the identity matrix?

Answer 5

but i got the answer...it has no inverse because there is a row of zeros when i worked it out

Answer 6

Did you take the determinant?

Answer 7

i row reduced it with the identity matrix

Answer 8

Ok. Well, you have the correct answer, it's not invertible. The determinant = 0.

Answer 9

ok thank you!