A square matrix is singular whenever:

(a) Solve the recurrence equations
$$\,\,\,\,\,\,\,\,\,T\left( n \right) = T\left( {n - 1} \right) + n$$
$$\,\,\,\,\,\,\,\,\,T\left( 1 \right) = 1T$$
(b) What is the generating function?
$$\,\,\,\,\,\,\,\,\,G\left( z \right)$$ for the sequence of Fibonacci numbers?

State whether the following statement are TRUE or FALSE:
(a) The union of two equivalence relations is also an equivalence relation.

A critical region is: