The first, second and the last terms of an A.P. are a,b and 2 a respectivley, show that its su is `(3ab)/(2(b-a))`

First , second and middle terms of an A.P. are a,b,c respectively . The sum of AP is :

The first and last terms of an A.P. are a and l respectively. Show that the sum of nth term from the beginning and nth term from the end is a + l.

Sum of the first p, q and r terms of an A.P. are a, b and c, respectively. Prove that a/p(q-r)+b/q(r-p)+c/r(p-q)=0

Find the 3rd term of A.P if a=1 , d=2

The 2nd, 31st and last terms of an A.P. are 7 3/4, 1/2 and -6 1/2 respectively, find the first term and the number of terms.

If the first and the nth term of a G.P. are a and b. respectively, and if P is the product of n terms, prove that P^2 = (ab)^n .

The p^(th) , q^(th) and r^(th) terms of an A.P. are a, b, c, respectively. Show that (q -r)a+ (r-p )b + (p- q)c= 0

If ‘a’ is the first term, ‘d' the common difference and 'l' the last term of an A.P., then the sum of the series is : (l^2-a^2)/(2d)+1/2(a+l) .

Sum of first p,q and r terms of an A.P. are a,b,c respectively. Prove that a/p(q-r) +b/q(r-p) + c/r(p-q)=0 .

The first term of an A.P. is a, the second term is b and last term is c. Show that the sum of A.P. is : ((b+c-2a)(c+a))/(2(b-a)) .