Home
Class 12
MATHS
If sum of n terms of a sequence is given...

If sum of n terms of a sequence is given by `S _(n) = 2n ^(2) - 4n,` find its `50^(th)` term.

Text Solution

AI Generated Solution

The correct Answer is:
To find the 50th term of the sequence where the sum of the first n terms is given by \( S_n = 2n^2 - 4n \), we can follow these steps: ### Step 1: Understand the relationship between the sum of terms and individual terms The nth term of the sequence, denoted as \( T_n \), can be found using the formula: \[ T_n = S_n - S_{n-1} \] This means that to find the nth term, we need to subtract the sum of the first \( n-1 \) terms from the sum of the first \( n \) terms. ### Step 2: Calculate \( S_{50} \) Using the given formula for \( S_n \): \[ S_{50} = 2(50^2) - 4(50) \] Calculating this step by step: \[ 50^2 = 2500 \] \[ S_{50} = 2(2500) - 4(50) = 5000 - 200 = 4800 \] ### Step 3: Calculate \( S_{49} \) Now we need to calculate \( S_{49} \): \[ S_{49} = 2(49^2) - 4(49) \] Calculating this step by step: \[ 49^2 = 2401 \] \[ S_{49} = 2(2401) - 4(49) = 4802 - 196 = 4606 \] ### Step 4: Find \( T_{50} \) Now, we can find \( T_{50} \): \[ T_{50} = S_{50} - S_{49} = 4800 - 4606 \] Calculating this gives: \[ T_{50} = 194 \] ### Final Answer Thus, the 50th term of the sequence is: \[ \boxed{194} \]
Promotional Banner

Topper's Solved these Questions

  • SEQUENCE & SERIES

    RESONANCE ENGLISH|Exercise SELF PRACTICE PROBLEMS |23 Videos
  • SEQUENCE & SERIES

    RESONANCE ENGLISH|Exercise EXERCISE -1 PART -I RMO|43 Videos
  • RELATION, FUNCTION & ITF

    RESONANCE ENGLISH|Exercise SSP|55 Videos
  • TEST PAPER

    RESONANCE ENGLISH|Exercise MATHEMATICS|48 Videos

Similar Questions

Explore conceptually related problems

If the sum of n terms of a sequence is given by S_(n)=3n^(2)-2nAA n in N , then its 10th term is

If S_n , the sum of first n terms of an A.P., is given by S_n=5n^2+3n , then find its n^(t h) term.

If the sum of n terms of an AP is given by S_(n) = (2n^(2)+3n) then find its common differnece.

Find the sum to n terms of the sequence given by a_n=2^n,n in Ndot

The nth term of a sequence is given by a_n=2n+7. Show that it is an A.P. Also, find its 7th term.

The nth term of a sequence is given by a_n=2n+7. Show that it is an A.P. Also, find its 7th term.

If S_n the sum of first n terms of an AP is given by 2n^2+n , then find its nth term.

If the sum of n terms of an A,Pis given by S_(n) =3n+2n^(2) then the common difference of the A.P. is

The nth term of a sequence is 3n-2 is the sequence an A.P.? If so, find its 10th term.