Given data
- Geometric series of powers of 2: 2 + 2^2 + 2^3 + … + 2^9.
- Notation note: The original text '22, 23, …, 29' is interpreted as 2^2, 2^3, …, 2^9 (consistent with typical formatting issues in plain text). This preserves all numbers and the crux.
Concept / Approach
- For a geometric series a + ar + ar^2 + … + ar^{n-1}, the sum is S = a(1 − r^n)/(1 − r) for r ≠ 1.
- Here a = 2, r = 2, and terms run from exponent 1 to 9 (9 terms).
Step-by-step calculation
S = 2 + 2^2 + … + 2^9 = (2^1 + 2^2 + … + 2^9)= \u2211_{k=1}^{9} 2^k = (2^{10} − 2^1)= 1024 − 2 = 1022
Verification / Alternative
Direct check (partial sums): 2 + 4 = 6; +8 = 14; +16 = 30; +32 = 62; +64 = 126; +128 = 254; +256 = 510; +512 = 1022.
Common pitfalls
- Including 2^0 = 1 by mistake (that would give 2^{10} − 1 = 1023).
- Misreading the plain-text exponents as multi-digit numbers.
Final Answer
1022
Discussion & Comments