Question

ii) If the first term of an A.P is a, the second term is b & the last term C, then show that the sum of the terms of the A.p (a + c) (btc-2a) /
2 (b-a)​

Answer 1

Answer:

(a + c)(b + c - 2a)/ 2(b - a)

Step-by-step explanation:

The common difference d is b - a.

The Sum of n terms = (n/2)(a + c).

Number of terms n = (c - a)/d  + 1

= [(c - a)/(b - a)] + 1.

So substituting for n:

Sum of the terms = [(c - a)/(b - a) + 1] / 2 * (a + c)

= (a + c)(b + c - 2a)/ 2(b - a)