Question

If the common difference of an A.P is d, find a3 – a1

Answer 1

2d

Explanation:

The n th term of an AP is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference, thus

a₃ - a₁

= a₁ + 2d - a₁

= 2d