-
One of the eigen vectors of the matrix A = 2 2 is 1 3
-
-
2 -1 -
2 1 -
4 1 -
1 -1
-
Correct Option: A
Given : A = | ![]() | 2 | 2 | ![]() | |||
1 | 3 |
Characteristic equation is | A – λI| = 0
⇒ | ![]() | 2-λ | 2 | ![]() | = 0 | ||
1 | 3-λ |
⇒ (2 – λ) (3 – λ) – 2 = 0
⇒ λ² – 5 + 4 = 0
⇒ λ = 1, 4
Eigen vector for λ = 1 is
![]() | 2-λ | 2 | ![]() | ![]() | x1 | ![]() | = 0 | |||
1 | 3-λ | x2 |
⇒ | ![]() | 1 | 2 | ![]() | ![]() | x1 | ![]() | = 0 | ||
1 | 1 | x2 |
⇒ x1 + 2x2 = 0
⇒ x2 = - 1/2 x
i.e. x1 : x2 = – 2 : 1
Since choice (a) | ![]() | 2 | ![]() | is in same ratio of x1 to x2 |
-1 |
∴ choice (a) is an eigen vector.