Saturday

January 31, 2015

January 31, 2015

Posted by **Lucas** on Sunday, February 3, 2013 at 4:35pm.

2..a new sequence is formed by adding together the corresponding terms of a geometric sequence and an arithmetic sequence.The common ratio of the geometric sequence is 2 and the common difference of the arithmetic sequence is 2.The first term of the new sequence is 1,and the second term is 7...

2.1 calculate the third term of the new sequence

2.2write down an expression for the n-th term of the new sequence

- Maths -
**Steve**, Sunday, February 3, 2013 at 5:23pma+d = ar

a = 12

r < 1

3/2 (2a+2d) = a(1+r+r^2) - 4/3

3ar = a(1+r+r^2) - 4/3

36r = 12(1+r+r^2) - 4/3

r = 2/3 or 4/3

r=2/3:

12+d = 12* 2/3

d = -4

AP = 12 8 4 0 ...

GP = 12 8 16/3 32/9 ...

check

12+8+4 = 12+8+16/3 - 4/3 YES

**Answer this Question**

**Related Questions**

Math (Geometric Progression) - 5 distinct positive reals form an arithmetic ...

maths - 1) The first term of arithmetic progression is -20 and the sum of it's ...

Arithmetic - The first, second and third terms of a geometric progression are 2k...

Math - 5 distinct positive reals form an arithmetic progression. The 1st, 2nd ...

arithmetic - Two arithmetic progression have thd same first and last terms.the ...

arithmetic - Each term of a progression is determined by adding 0.5 to the ...

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

maths - the sum of the 4th and 6th terms of an A.P is 42. the sum of the 3rd and...

Maths - An arithmetic and a geometric sequence have the same first terms.(2).......

Maths - Arithmetic Progression - The fourth term of an AP is 8 and the sum of ...