SOLUTION: an n x n matrix A is nilpotent if A^r=0 for some positive integer (a)give an example of a nonzero nilpotent 2 x 2 matrix (b)show that if A is invertible matrix,then A is not ni

Algebra ->  Matrices-and-determiminant -> SOLUTION: an n x n matrix A is nilpotent if A^r=0 for some positive integer (a)give an example of a nonzero nilpotent 2 x 2 matrix (b)show that if A is invertible matrix,then A is not ni      Log On


   



Question 1062853: an n x n matrix A is nilpotent if A^r=0 for some positive integer
(a)give an example of a nonzero nilpotent 2 x 2 matrix
(b)show that if A is invertible matrix,then A is not nilpotent

Answer by ikleyn(52790) About Me  (Show Source):
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an n x n matrix A is nilpotent if A^r=0 for some positive integer
(a)give an example of a nonzero nilpotent 2 x 2 matrix
(b)show that if A is invertible matrix,then A is not nilpotent
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a) An example is A = %28matrix%282%2C2%2C+0%2C1%2C+0%2C0%29%29. Check that A%5E2 = 0.


b) If a matrix A is nilpotent, then det(A) = 0  (determinant).


   From the other side, if a matrix A is invertible, then its determinant is not zero.