a2=3 a2=aq a6=243 a6=aq^5 3=aq => 3/q=a 243=aq^5 243= 3/q * q^5 243= 3q^4 81=q^4 q=3 a= 3/3 a=1 S8= a * (1- q^8)/(1-q) S8= 1 * (1- 3^8)(1-3) S8= (1-6561)/(-2) S8= 3280
a2 = 3 a6 = 243 a2 = a1*q a6 = a1*q^5 ----------------- a6 : a2 = a1*q^5 : a1*q = q^4 a6 : a2 = 243 : 3 = 81 q^4 = 81 q = 3 a2 = a1*q ---> a1 = a2 : q = 3 : 3 = 1 a1 = 1 a8 = a1*q^7 = 1*3^7 = 2187 S8 = [1 - q^8]/[ 1-q] = [1-6561]/[1-3] = (-6560)/(-2) = 3280
Oblicz sume 8 wyrazow ciagu geonetrycznego, w ktorym a2=3, a6=243 a6/ a2=g⁴=243/3 g⁴=81 g=3 a1=1 S8=1*(1-3⁸)/(1-3) S8=(1-3⁸)/(-2) S8=(1-6561)/(-2) S8=(-6560)/(-2) S8=3280
Rozwiaz rownanie: A) 1+7+13+19+...+x=280 B) Oblicz sume 8 wyrazow ciagu geonetrycznego, w ktorym a2=3, a6=243
Rozwiaz rownanie: A) 1+7+13+19+...+x=280 B) Oblicz sume 8 wyrazow ciagu geonetrycznego, w ktorym a2=3, a6=243...