The number of equivalence relations on the set $$\left\{ {1,2,3,4} \right\}$$ is

The determination of the matrix $$$\left[ {\matrix{ 6 & { - 8} & 1 & 1 \cr 0 & 2 & 4 & 6 \cr 0 & 0 & 4 & 8 \cr 0 & 0 & 0 & { - 1} \cr } } \right]\,\,is$$$

Let $$A = ({a_{ij}})$$ be and n-rowed square matrix and $${I_{12}}$$ be the matrix obtained by interchanging the first and second rows of the n-rowed Identity matrix. Then$${AI_{12}}$$ is such that its first

What is the maximum value of the function
$$f\left( x \right) = 2{x^2} - 2x + 6$$ in the interval $$\left[ {0,2} \right]$$?