WebJul 25, 2024 · Solution : nth term in the AP , Common difference (d) = 2 Sum of the series is ..... (1) Sum of the series Since n should be a positive integer. So we take n = 7 Substitute in equation (1), The first term is a=-8 and number of terms is n=7. #Learn more If nth term of an A.P is 4+3n, find first two terms of A.P brainly.in/question/12877971 WebFor an AP, S n = (n/2) [2a+ (n-1)d] Putting n = n-1 in above equation, l is the last term. It is also denoted by a n. The result obtained is: S n -S n-1 = a n So, 441-356 = a n a n = 85 = 13+ (n-1)d Since d=n, n (n-1) = 72 ⇒n 2 – n – 72= 0 Solving by factorization method, n 2 -9n+8n-72 = 0 (n-9) (n+8)=0 So, n= 9 or -8
In an AP, if Sn = n (4n + 1), then find the AP. - Sarthaks
WebAug 26, 2024 · The sum of the first n terms of an AP is given by Sn, = 3n^2 - 4n. Determine the AP and the 12th term. asked Feb 1, 2024 in Mathematics by Kundan kumar ( 51.5k points) WebMar 29, 2024 · Given a = 7, a13 = 35 We need to find d We know that an = a + (n – 1) d Putting a = 7, n = 13 and an = 35 35 = 7 + (13 – 1) × 𝑑 35 = 7 + 12d 35 – 7 = 12d 28 = 12 d 28/12=𝑑 7/3=𝑑 d = 𝟕/𝟑 Now we need to find S13 We can use formula Sn = 𝒏/𝟐 (𝒂+𝒍) Putting n = 13, a = 7, 𝑙 = a13 = 35 = 13/2 (7+35) = 13/2 × 42 = 13 × 21 = 273 és jött a doktor
In an AP, given a = 2 , d = 8 , Sn = 90 , find n and an - Toppr
WebApr 6, 2024 · Class 10 ll Arithmetic Progression Ex :- 5.3 ll Question no.3 In an AP(viii) Given an=4, d=2, Sn=-14, Find 'n' and 'a'.Arithmetic Progression Ex :- 5.1Questi... WebNov 6, 2013 · (viii) Given that, a n = 4, d = 2, S n = −14. a n = a + (n − 1)d. 4 = a + (n − 1)2. 4 = a + 2n − 2. a + 2n = 6. a = 6 − 2n (i) −28 = n (a + 4) −28 = n (6 − 2n + 4) {From equation (i)} … WebMar 29, 2024 · And, the formula to calculate sum of first n terms of an AP, that is S n, is given by, S n = n 2 ( 2 a + ( n − 1) d) ⋯ ⋯ ( i i) Now, In the given question we have, a n = 4, d = 2. Using these values in equation ( i) , we can write, a + ( n − 1) 2 = 4. Applying distributive law, we get, a + 2 n − 2 = 4. hayat sarkisi 5