Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
osanseviero
Group Title
In a geometric series,
a2=6
a5=48
Which is the first term, which is the constant and write the progression
 one year ago
 one year ago
osanseviero Group Title
In a geometric series, a2=6 a5=48 Which is the first term, which is the constant and write the progression
 one year ago
 one year ago

This Question is Closed

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
I know that \[an=a1*r ^{n1}\] What goes next?
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
6=a1*r^(n1) ?
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
6=a1*r^(21), 6=a1*r
 one year ago

Noura11 Group TitleBest ResponseYou've already chosen the best response.2
As you said : \[a_n=a_1\times q^{n1}\] where q is the constant of the serie, so we have : \[a_2=a_1\times q\\a_5=a_1\times q^4\] Is that true ?
 one year ago

Noura11 Group TitleBest ResponseYou've already chosen the best response.2
so we get : \[6=a_1\times q~~~~~~(1)\\48=a_1\times q^4~~~(2)\] Now, we can divide the equation (2) over (1) , what should we get ?
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
8=q^3, q=2!
 one year ago

Noura11 Group TitleBest ResponseYou've already chosen the best response.2
Good. Now the 1st term can be found easily, can't it ?
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
yepp :D
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
3 :) thanks
 one year ago

osanseviero Group TitleBest ResponseYou've already chosen the best response.0
So an=3*2^n1 ?
 one year ago

Noura11 Group TitleBest ResponseYou've already chosen the best response.2
Yes, it is ! And you are welcome !
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.