Odpowiedzi

2009-10-10T16:46:06+02:00
A = a_1
q - iloraz ciągu

a_1 + a_5 = 68
a_2 + a_6 = 136

a + aq⁴ = 68
aq + aq⁵ = 136

a + aq⁴ = 68
q(a + aq⁴) = 136

a + aq⁴ = 68
q* 68 = 136

q = 136/68 = 2

a + aq⁴ = 68
a + 16a = 68
17a = 68
a = 4

q = 2 i a = 4

S_n = a(1 - q^n)/(1 - q)
2044 = 4(1 - 2^n)/(1 - 2)
2044 = 4(1 - 2^n)/(-1)
511 = 2^n - 1
512 = 2^n
n = log_2 (512)

n = 9