- #1
dagg3r
- 67
- 0
hi all just got stuck on these questions on matrices just wondering if anyone can help me out thanks
1. For which values of k is the folowing equation satisfied?
|3-k 5 |
= 0
|4 4-k |
its all in a matrix. I am thinking it is the determinant =0 so
(3-k)(4-k) - 20 = 0
12-7k-k^2 - 20 = 0
-k^2-7k-44=0
then we solve for k? that's out ans?
2. IF A is a matrix or order 2x1, B is 2x3 and C is 3x3 which of the folowing is defined?
a) ABC
b) AT B ( a is transposed * B)
c) BCT + AT (B*Ctransposed + Atransposed)
well i know a) cannot be defined since when you multiply matrices must be the order ie 2x1 * 1x3 etc but won't work
b) can be defined
c) confused since adding matrices not sure how that works.
please reply
thanks
1. For which values of k is the folowing equation satisfied?
|3-k 5 |
= 0
|4 4-k |
its all in a matrix. I am thinking it is the determinant =0 so
(3-k)(4-k) - 20 = 0
12-7k-k^2 - 20 = 0
-k^2-7k-44=0
then we solve for k? that's out ans?
2. IF A is a matrix or order 2x1, B is 2x3 and C is 3x3 which of the folowing is defined?
a) ABC
b) AT B ( a is transposed * B)
c) BCT + AT (B*Ctransposed + Atransposed)
well i know a) cannot be defined since when you multiply matrices must be the order ie 2x1 * 1x3 etc but won't work
b) can be defined
c) confused since adding matrices not sure how that works.
please reply
thanks