Sunday

April 20, 2014

April 20, 2014

Posted by **Anonymous** on Sunday, November 11, 2012 at 2:30pm.

1.25, 3.5, 8, 17, 35, 71, ___, ___, 575,...

- math -
**Reiny**, Sunday, November 11, 2012 at 5:37pmIf you make a difference table, you will see that

they are:

1.25, 4.5 , 9 , 18 , 36

starting at the second the difference is twice the previous difference

e.g t5 = t4 + 2(t4 - t3) = 3t4 - 2t3

in general

t(n+1) = 3t(n) - 2t(n-1) , n> 2, t(1) = 1.25 , t(2) = 3.5

so

t(7) = 3t(6) - 2t(5) = 3(71)-2(35) =**143**

t(8) = 3t(7) - 2t(6) = 3(143) - 2(71) =**287**

check:

t(9) = 3t(8) -2t(7) = 3(287) - 2(143 =**575**, YEAHHH

**Related Questions**

Math - What are the missing numbers in this sequence? 1.25, 3.5, 8, 17, 35, 71, ...

math - An arithmetic sequence is represented in the following table. Enter the ...

Math - Three different numbers are chosen at random from the set {1,2,3,4,5}. ...

Math - Three different numbers are chosen at random from the set {1,2,3,4,5}. ...

math - Three dierent numbers are chosen at random from the set f1; 2; 3; 4; 5g...

math - Is there a common ratio for the geometric sequence and what are the ...

math - The Fibonacci sequence of numbers begins 1,1,2,3,5,8,13,21,34,55,…and ...

Algebra - Predict the next two numbers in this sequence. Leave a comma but no ...

Math Concepts - What is the difference between an arithmetic sequence and a ...

math - Three numbers in an arithmetic sequence sum to six. If you add 1 to the ...