Compute the Frobenius norm of the matrix B=(1234)B = \begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}B=(1324), defined as ∥B∥F=∑i,jbij2\|B\|_F = \sqrt{\sum_{i,j} b_{ij}^2}∥B∥F=∑i,jbij2.
10\sqrt{10}10
20\sqrt{20}20
30\sqrt{30}30
40\sqrt{40}40