- #1
mr_coffee
- 1,629
- 1
Hello everyone, i have no idea why i can't grasp this simple concept...
i have:
A =
1 4 9
0 1 9
0 0 1
I have to find A^-1, A inverse.
So I found the determinant along row 3,
1*det(B) = 1;
B =
1 4
0 1
det(B) = (1)(1) - (4)(0) = 1;
so i take 1/det * A now wouldn't that just be A itself?
When i submitted the answer
A inverse =
1 4 9
0 1 9
0 0 1
it said,
Entered Answer Preview Result
1 1 correct
4 4 incorrect
9 9 incorrect
0 0 correct
1 1 correct
9 9 incorrect
0 0 correct
0 0 correct
1 1 correct
i have:
A =
1 4 9
0 1 9
0 0 1
I have to find A^-1, A inverse.
So I found the determinant along row 3,
1*det(B) = 1;
B =
1 4
0 1
det(B) = (1)(1) - (4)(0) = 1;
so i take 1/det * A now wouldn't that just be A itself?
When i submitted the answer
A inverse =
1 4 9
0 1 9
0 0 1
it said,
Entered Answer Preview Result
1 1 correct
4 4 incorrect
9 9 incorrect
0 0 correct
1 1 correct
9 9 incorrect
0 0 correct
0 0 correct
1 1 correct