For the system     The value of a for which system must not be controllable is ___Select one:a. 1b. 0c. 3d. -3

To determine the value of 'a' for which the system must not be controllable, we need to analyze the controllability condition. The controllability matrix for a system is given by:

C = [B, AB, A^2B, ..., A^(n-1)B]

where A is the system matrix and B is the input matrix. The system is controllable if and only if the rank of the controllability matrix is equal to the number of states of the system.

In this case, since the system is not specified, we cannot directly calculate the controllability matrix. However, we can make some general observations.

If the system is not controllable, it means that there exists at least one state that cannot be controlled by the input. This can happen if the columns of the controllability matrix are linearly dependent, i.e., one column can be expressed as a linear combination of the other columns.

To find the value of 'a' for which the system is not controllable, we need to analyze the system matrix A and input matrix B. Without any specific information about these matrices, it is not possible to determine the exact value of 'a' for which the system is not controllable.

Therefore, the answer to the question cannot be determined without additional information about the system.