Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

sum_(k=0)^(19)-4(-2)^(k)~~
Choose 1 answer:
(A) 
-699,052
(B) 
1,398,100
(c) 
2,097,152
(D) 
4,194,308

k=0194(2)k \sum_{k=0}^{19}-4(-2)^{k} \approx \newlineChoose 11 answer:\newline(A) 699,052 -699,052 \newline(B) 1,398,100 1,398,100 \newline(C) 2,097,152 2,097,152 \newline(D) 4,194,308 4,194,308

Full solution

Q. k=0194(2)k \sum_{k=0}^{19}-4(-2)^{k} \approx \newlineChoose 11 answer:\newline(A) 699,052 -699,052 \newline(B) 1,398,100 1,398,100 \newline(C) 2,097,152 2,097,152 \newline(D) 4,194,308 4,194,308
  1. Identify series type: Identify the type of series.\newlineThe series is of the form 4(2)k-4(-2)^k, which is a geometric series because each term is obtained by multiplying the previous term by a common ratio.
  2. Determine first term: Determine the first term of the series.\newlineThe first term is obtained when k=0k=0, which gives us 4(2)0=4(1)=4-4(-2)^0 = -4(1) = -4.
  3. Determine common ratio: Determine the common ratio of the series.\newlineThe common ratio is 2-2, as each term is multiplied by 2-2 to get the next term.
  4. Use formula for sum: Use the formula for the sum of a finite geometric series.\newlineThe sum SS of a geometric series with first term aa, common ratio rr, and nn terms is given by S=a(1rn)(1r)S = \frac{a(1 - r^n)}{(1 - r)}, provided that r1r \neq 1.
  5. Apply formula to series: Apply the formula to the given series.\newlineHere, a=4a = -4, r=2r = -2, and n=20n = 20 (since we are summing from k=0k=0 to k=19k=19, which gives us 2020 terms).\newlineS=4(1(2)20)/(1(2))S = -4(1 - (-2)^{20}) / (1 - (-2))
  6. Calculate sum: Calculate the sum.\newlineS=4(1220)/(1+2)S = -4(1 - 2^{20}) / (1 + 2)\newlineS=4(11048576)/3S = -4(1 - 1048576) / 3\newlineS=4(1048575)/3S = -4(-1048575) / 3\newlineS=4×1048575/3S = 4 \times 1048575 / 3\newlineS=4194300/3S = 4194300 / 3
  7. Final calculation: Final calculation.\newlineS=1398100S = 1398100

More problems from Geometric sequences