Ответ:
В решении.
Объяснение:
1) b₁ = -18; q = 1/2; b₈ = ?
Формула:
bn = b₁ * qⁿ⁻¹;
b₈ = -18 * (1/2)⁷
b₈ = -18 * 1/128
b₈ = -9/64;
2) b₁ = 8; q = 2; S₁₀ = ?
Sn = [b₁ * (qⁿ - 1)]/(q - 1);
S₁₀ = [8 * (2¹⁰ - 1)]/(2 - 1)
S₁₀ = [8 * (1024 - 1)]
S₁₀ = (8 * 1023)
S₁₀ = 8184;
3) b₁ = 9; b₂ = 12; b₃ = 16; S₆ = ?
a) Найти q:
q = b₂/b₁
q = 12/9
q = 4/3;
б) Найти S₆:
S₆ = [9 * ((4/3)⁶ - 1)]/(4/3 - 1)
S₆ = [9 * (4096/729 - 1)]/1/3
S₆ = [9 * (5 451/729 - 1)]/1/3
S₆ = [9 * (4 451/729)] : 1/3
S₆ = (9 * 3367/729) : 1/3
S₆ = 3367/81 : 1/3
S₆ = 124 19/27.
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Ответ:
В решении.
Объяснение:
1) b₁ = -18; q = 1/2; b₈ = ?
Формула:
bn = b₁ * qⁿ⁻¹;
b₈ = -18 * (1/2)⁷
b₈ = -18 * 1/128
b₈ = -9/64;
2) b₁ = 8; q = 2; S₁₀ = ?
Формула:
Sn = [b₁ * (qⁿ - 1)]/(q - 1);
S₁₀ = [8 * (2¹⁰ - 1)]/(2 - 1)
S₁₀ = [8 * (1024 - 1)]
S₁₀ = (8 * 1023)
S₁₀ = 8184;
3) b₁ = 9; b₂ = 12; b₃ = 16; S₆ = ?
a) Найти q:
q = b₂/b₁
q = 12/9
q = 4/3;
б) Найти S₆:
Формула:
Sn = [b₁ * (qⁿ - 1)]/(q - 1);
S₆ = [9 * ((4/3)⁶ - 1)]/(4/3 - 1)
S₆ = [9 * (4096/729 - 1)]/1/3
S₆ = [9 * (5 451/729 - 1)]/1/3
S₆ = [9 * (4 451/729)] : 1/3
S₆ = (9 * 3367/729) : 1/3
S₆ = 3367/81 : 1/3
S₆ = 124 19/27.