Advertisements
Advertisements
प्रश्न
Find the sum `[("a" - "b")/("a" + "b") + (3"a" - 2"b")/("a" + "b") + (5"a" - 3"b")/("a" + "b") + ... "to" 12 "terms"]`
उत्तर
= `1/("a" + "b") [("a" - "b") + (3"a" - 2"b") + (5"a" - 3"b") + ... 12 "terms"]`
Here a = `("a" - "b")/("a" + "b"), "d"` = t2 – t1
= `(3"a" - 2"b")/("a" + "b") - ("a" - "b")/("a" + "b")`
d = `(2"a" - "b")/("a" + "b")`
∴ Sn = `"n"/2 (2"a" + ("n" - 1)"d")`
S12 = `12/2[2(("a" - "b")/("a" + "b")) + 11 xx ((2"a" - "b")/("a" + "b"))]`
= `6[(2"a" - 2"b" + 22"a" - 11"b")/("a" + "b")]`
= `6[(24"a" - 13"b")/("a" + "b")]`
APPEARS IN
संबंधित प्रश्न
Find the sum of the following
3, 7, 11, … up to 40 terms
Find the sum of the following
102, 97, 92, … up to 27 terms.
Find the sum of the following
6 + 13 + 20 + .... + 97
How many consecutive odd integers beginning with 5 will sum to 480?
Find the sum of first 28 terms of an A.P. whose nth term is 4n – 3
Find the sum of all natural numbers between 602 and 902 which are not divisible by 4.
Raghu wish to buy a laptop. He can buy it by paying ₹ 40,000 cash or by giving it in 10 installments as ₹ 4800 in the first month, ₹ 4750 in the second month, ₹ 4700 in the third month and so on. If he pays the money in this fashion, find total amount paid in 10 installments
A man repays a loan of ₹ 65,000 by paying ₹ 400 in the first month and then increasing the payment by ₹ 300 every month. How long will it take for him to clear the loan?
A brick staircase has a total of 30 steps. The bottom step requires 100 bricks. Each successive step requires two bricks less than the previous step
How many bricks are required to build the stair case?
If A = 265 and B = 264 + 263 + 262 …. + 20 identify of the following is true?
