Question

Let A be a matrix of order 3 × 4. If R₁ denotes the first row of A and C₂ denotes its second column, then determine the orders of matrices R₁ and C₂

Answer 1

A is a matrix of order 3 × 4

⇒ A has 3 rows and 4 columns

A = `[("a"_11,"a"_12,"a"_13,"a"_14),("a"_21,"a"_22,"a"_23,"a"_24),("a"_31,"a"_32,"a"_33,"a"_34)]`

Now, Row 1 i.e. R₁ = `[("a"_11,"a"_12,"a"_13,"a"_14)]`, it has 4 columns

So, order of R₁ is 1 × 4

Column 2 i.e. C₂ = `[("a"_12),("a"_22),("a"_32)]`, it has 1 column and 3 rows

So, order of C₂ is 3 × 1.