Matrix Addition is Element-by-Element
Add same-order matrices by summing the cells that share an address.
Equation
y = x + 1
Graph
Table
| x | y |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 4 | 5 |
| 5 | 6 |
| 6 | 7 |
| 7 | 8 |
| 8 | 9 |
| 9 | 10 |
What this lesson covers
What you do
You shape the function y = x + b and watch the graph answer.
Challenges to clear
- Set b = 5: the entry 1 becomes 6 — cells that share an address add together.
- Same b: the entry 6 becomes 11. Every cell shifts by the same partner cell.
- Add the matrix to ITSELF first, then to a second one: slide a to 2.
- Now the partner matrix: an entry of 3 must finish on 13. Cells only ever combine with the cell at the same address.
Check yourself
Can you add a 2x3 matrix to a 3x2 matrix?
- No — the orders must match exactly (rows AND columns) for element-wise addition. — correct
- Yes, by transposing one of them first.
- Yes, by ignoring the extra cells.
- Only if both contain only positive integers.
Think about it
- Matrix addition is cell-by-cell: if a₁₁ = 1 and b₁₁ = 5, what is c₁₁?