Question

Geometric Progressions Grade 11 Help please?

I have to find the sum.

Answer 1

a = 1 , r = (p-1)/p and n = p

Formula is : Sn = a(1 - r^n)/(1 - r)

The answer is :

(P^P - (p-1)^P) / P^P-1


i don't know how to get to the answer =/........can someone help me please

Answer 2

sorry, the answer is The answer is :

(P^P - (p-1)^P) / P^(P-1), forgot a backet

Answer 3

This is an algebra problem.
\[\frac{1- \frac{(p-1)^p}{p^p}}{1- \frac{(p-1)}{p}}\]

Answer 4

multiply top and bottom by p

Answer 5

Do you see what happens to the bottom?

Answer 6

@phi maybe p +1 instead of p? as the exponent i mean

Answer 7

hmm

Answer 8

he said the exponent was n, and n was = p, unless I mis-read the question

Answer 9

usually it mean you have n terms and sum is
\[\frac{1-r^{n+1}}{1-r}\]

Answer 10

Sn = a(1 - r^n)/(1 - r)

Answer 11

oh my fault i did not read carefully. ignore me

Answer 12

n = p , and the formula we're given is a(1 - r^n)/(1 - r) :)

Answer 13

What happens to the denominator P^P if I multiply both top and bottom by p?

Answer 14

did you try?

Answer 15

although in my defense
\[S_n=\frac{a(1-r^{n+1})}{1-r}\]

Answer 16

so the bottom part becomes -1/p

Answer 17

The bottom is
\[ 1- \frac{(p-1)}{p} \]

Answer 18

actually satellite73 Sn = a(1 - r^n)/(1 - r)

Answer 19

yeah

Answer 20

so what is
\[ p(1 - \frac{(p-1)}{p})\]

Answer 21

p - p - 1 ? = -1

Answer 22

pretty close. you distribute the p (that means multiply every term in the parens by p to get
p - (p-1)
now distribute the - sign

Answer 23

opps! thanks for correcting me

Answer 24

I'll try to go on from here..thank you ~~

Answer 25

so the bottom goes away (becomes 1), and dividing by 1 can be ignored.
to finish, multiply the top by p
then find a common denominator to simplify

Answer 26

YAY!!!!!!!!

Answer 27

Thank you!! :))