21.3.1. Addition and Subtraction

Try these first

1. 1.

   What is A + B if A = [[1, 2], [3, 4]] and B = [[5, 6], [7, 8]]?

   Hint

   Add corresponding elements of each matrix.

2. 2.

   If C = [[3, 3], [3, 3]], what is C - C?

   Hint

   Subtract elements from themselves.

3. 3.

   Can you add a 2x3 and a 3x2 matrix?

   • True
   • False

   Hint

   Think about the shape of each matrix.

4. 4.

   What is the first element of the resulting matrix if A = [[1,2], [3,4]] and B = [[5,6], [7,8]]?

   • 1
   • 5
   • 6
   • 7

   Hint

   Look at the top left corner of both matrices.

5. 5.

   Prove that the sum of a matrix and its negative matrix results in a zero matrix through an example.

   Hint

   Subtract each element from itself.

6. 6.

   A will be a 3x3 matrix with all elements equal to 1. Describe the addition of this matrix with a 3x3 matrix having all elements equal to 2.

   Hint

   Look at the total number of elements when you add them!