Question

Find the 6th partial sum of
http://seminole.flvs.net/webdav/assessment_images/educator_algebra2_v10/09_07c_3_02.gif

Answer 1

@Hero

Answer 2

you will have to write the question here
unable to log in to your course

Answer 3

ok
infinite sigma 7(4) i=1 i-1

Answer 4

i can't understand what you wrote, but the 6th partial sum means add up the first six terms

Answer 5

it's an infinity sign above the greek E and to the right is 7(4)^i-1.
Underneath the E is i=1

Answer 6

@mathsolver @terenzreignz @satellite73 @khkulla

Answer 7

Infinity symbol
i-4
E 7(4)
i=1

Answer 8

sounds like fun... :D
\[\Large \sum_{i=1}^\infty 7(4)^{i-1}\]
yes?

Answer 9

a)78,432

b) 11,204

c)9,555

d) 2,387

Answer 10

yes

Answer 11

I don't know about you... but this looks like a divergent series to me...

Answer 12

it is

Answer 13

Oh, right, sixth partial sum... lol silly me :D

Answer 14

so, how do i solve it?

Answer 15

There is a formula for partial sums of geometric series... hang on...

Answer 16

We can write it like this, right?
\[\Large \sum_{i=0}^5 7(4)^{i}\]

Answer 17

yes

Answer 18

Which is great, because we have a formula for this particular form... here it is...
\[\Large \sum_{i=0}^{\color{red}n} \color{green}a\color{blue}r^{i}= \frac{\color{green}a(1-\color{blue}r^{\color{red}n+1})}{1-\color{blue}r}\]

Answer 19

Just plug in, and you're good to go :D

Answer 20

wait wat?

Answer 21

Pay attention to this form...
\[\Large \sum_{i=0}^{\color{red}n} \color{green}a\color{blue}r^{i}= \frac{\color{green}a(1-\color{blue}r^{\color{red}n+1})}{1-\color{blue}r}\]

Now, look at this... it's similar, we just have specific values for a, r, and n.
\[\Large \sum_{i=0}^\color{red}5 \color{green}7(\color{blue}4)^{i}\]

Answer 22

So just plug the appropriate values into this formula...
\[\Large \sum_{i=0}^{\color{red}n} \color{green}a\color{blue}r^{i}= \frac{\color{green}a(1-\color{blue}r^{\color{red}n+1})}{1-\color{blue}r}\]

And you'll have your sum :)

Answer 23

=7(1-4^(5+1))/1-4

Answer 24

That's it :D

Answer 25

And just calculate that :D

Answer 26

=7(1-4^6)/-3
=7(1-4096)/-3
=7(-4095)/-3
=-28672/-3
=9557.33

Answer 27

No way... I just googled this...
(7(1-(4^(5+1))))/(1-4)
And I didn't get that nasty decimal... could you run this through again?

Answer 28

must've messed up the math got 9555

Answer 29

it's right

Answer 30

haha... I'm awesome...
LOL Just kidding :D

We make a great team :)

Answer 31

:D ya we do and you are awesome.