why is the following statement true?
A (3x3) matrix A = (a subi,subj) is defined by (a subi, subj) = ij^2 for 1

Question

why is the following statement true? 
A (3x3) matrix A = (a subi,subj) is defined by (a subi, subj) = ij^2 for 1 <or=i, j < or = 3, then the sum of the entries in column 3 is 54

amistre64 · Answer

whats that in english?

amistre64 · Answer

11  12  13

21  22  23

31  32  33

rc^2   1 <= r ; and c <=3

i like to use r for row and c for column; makes more sense to me intuitively

amistre64 · Answer

there is only one row where r is equalto or less than 1

and all columns are less than or equal to 3

anonymous · Answer

ok, thanks

amistre64 · Answer

is that $$rc^2\ or, (rc)^2 $$

not that it matters since r=1

amistre64 · Answer

its hard to read; but i think it says the entries are rc^2 for all entries

amistre64 · Answer

1   4    9
2   8   18
3  12  27
---------
           54

amistre64 · Answer

well, it does work out