Monday

March 30, 2015

March 30, 2015

Posted by **Watermelon** on Thursday, December 1, 2011 at 8:37am.

(a)the first term and the common ration of the progression

(b)the sum of infinity of the progression

- GP Caluculus -
**bobpursley**, Thursday, December 1, 2011 at 8:51amCalculus, AP?

caluculus, fouth, ration, are not words normally used by Calculus students. Choosing words, and checking the spelling, reflects on you personally. If you desire success, work on these types of details. You can do better than this.

Given that a3 is 16, and a4 is 8, the ratio must be r=.5

a3=a0*r^(3-1)

16=a0*(1/2)^(3-1)or a0=16*4

check: 16*4, 16*2, 16*1, 16*1/2, ...

sum:

Sum= ao/(1-r)=16*4/.5=16*8

check my thinking.

- GP Caluculus -
**Watermelon**, Thursday, December 1, 2011 at 9:09amthis is not arithmetic progression = =

- GP Caluculus -
**Reiny**, Thursday, December 1, 2011 at 9:30amthird term = ar^2 and ar^2 = 16

fourth term = ar^3

ar^2 + ar^3 = 8

16 + ar^3 = 8

ar^3 = -8

ar^3/(ar^2) = -8/16

r = -1/2

then a = 64

terms are: 64 -32 16 -8 4 ...

check: is term3 = 16 ? , YES

is 16 - 8 = 8 ? , yes

sum_{∞}= a/(1-r) = 64/(3/2) = 128/3

- GP Caluculus -
**bobpursley**, Thursday, December 1, 2011 at 10:20amThanks, R. I mis-read the statement, I some how read into the question the fourth term was 8. Duh on me.

**Answer this Question**

**Related Questions**

GP Caluculus - The third term of a geometric progression is 16. The sum of the ...

GP Caluculus - The third term of a geometric progression is 16. The sum of the ...

Geometric progression - The second term of a geometric progression is 12 more ...

Math Algebra - The first term of a geometric progression is more than the third ...

Maths - 1..The first 2 terms of a geometric progression are the same as the ...

math - the fourth term of an arithmetic progression is equal to 3 times the ...

Math - The fifth term of an arithmetic progression is three times the second ...

Maths - A geometric progression has a third term of 20 band sum to infinity ...

math - In the geometric progression, the first is a and the common ratio is r. ...

geometric progression - the 3rd term of a gpis 10 and the 6th term is 80 find ...