a2 = 4
a5 = -32
n = 6
q ?
S6 = ?
an = a1 *q^(n-1)
a5 = a2 *q^3
-32 = 4 *q^3
q^3 = -32/4 = -8
q = ∛(-8)
q = -2
=====
Sn = a1 *(1-q^n)/(1-q), Z(q ≈1)
a1 = a2/q = 4/(-2) = -2
S6 = (-2) *[1-(-2)^6]/[1-(-2)] = (-2)*(1-64)/(1+2) = (-2)(-63)/3 = 126/3 = 42
S6 = 42
======
" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
a2 = 4
a5 = -32
n = 6
q ?
S6 = ?
an = a1 *q^(n-1)
a5 = a2 *q^3
-32 = 4 *q^3
q^3 = -32/4 = -8
q = ∛(-8)
q = -2
=====
Sn = a1 *(1-q^n)/(1-q), Z(q ≈1)
a1 = a2/q = 4/(-2) = -2
S6 = (-2) *[1-(-2)^6]/[1-(-2)] = (-2)*(1-64)/(1+2) = (-2)(-63)/3 = 126/3 = 42
S6 = 42
======