Question

Write the expression for the common difference of an A.P. whose first term is a and nth term is b.

Answer 1

The n^th term of the A.P whose first term a₁ and common difference is d is given by a_n = a + (n–1) d 

Here a_n is given as b

so b = a + (n–1) d

\(\cfrac{b - a}{n - 1}\) = d

⇒ d = \(\cfrac{b - a}{n - 1}\)