WebDec 19, 2024 · (iii) Sum of n terms of an AP is always quadratic in ‘n’ Example: S n = 2n 2 + 3n. Example: S n = n/4 (n + 1) we can find ‘d’ also from S n. d = 2 (coefficient of n 2) for eg. : 2n 2 + 3n, d = 2 (2) = 4 Verification: S n = 2n 2 + 3n at n = 1, S 1 = 2 + 3 = 5 = first term at n = 2, S 2 = 2 (2) 2 + 3 (2) = 8 + 6 = 14 ≠ second term WebMar 23, 2024 · The sum of the third and the seventh terms of an AP is 6 and their product is 8. Find the sum of first sixteen terms of the AP. 3. A ladder has rungs 25 cm apart. (see Fig. 5.7). The rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top.
Sum of the First n Terms of a Series - Varsity Tutors
WebIt is given that sum of the first n terms of an A.P. is 3n 2 + 6n. ∴ First term = a = S 1 = 3 (1) 2 + 6 (1) = 9. Sum of first two terms = S 2 = 3 (2) 2 + 6 (2) = 24. ∴ Second term = S 2 − S 1 = 24 − 9 = 15. ∴ Common difference = d = Second term − First term = 15 − 9 = 6 Also, n th term = a n = a + (n − 1)d ⇒ a n = 9 + (n − 1)6 ⇒ a n = 9 + 6n − 6 WebMar 27, 2024 · Solution For 10] Find the sum of first ' n ' terms of an AP 2 ,8 ,18 ,32 , 11] If α,β and γ are the zeroes of the polynomial P(x)=x3−6x2−x+30 then fin. The world’s only live instant tutoring platform. Become a tutor About us Student login Tutor login. Login. Student Tutor. Filo instant Ask button for chrome browser. ... smart android watches for men
Let Sn be the sum of the first n terms of an AP if S2n=3n+14n^2 ... - Quora
WebThe sum of n terms of an AP can be found using one of the following formulas: S n = n/2 (2a+ (n−1)d) S n = n/2 (a 1 +a n) Here, a = a 1 = the first term, d = the common difference, n = number of terms, a n = n th term, S n … WebTo find the sum of the first n terms of an arithmetic sequence use the formula, S n = n ( a 1 + a 2) 2 , where n is the number of terms, a 1 is the first term and a n is the last term. Example 1: Find the sum of the first 20 terms of the arithmetic series if a 1 = 5 and a 20 = 62 . S 20 = 20 ( 5 + 62) 2 S 20 = 670 Example 2: WebMar 30, 2024 · There are 2 AP s with different first term and common difference For the first AP Let first term be a common difference be d Sum of n term = Sn = /2 (2a + (n 1)d) & nth term = an = a + (n 1)d Similarly for second AP Let first term = A common difference = D Sn = /2 (2A + (n 1)D) & nth term = An = A + (n 1)D We need to find ratio of 12th term i.e. … smart animal rescue batlow