Question

The sequence is given by 4, -3, -10
1) is this sequence an AP or GP? Give the reasons
2) write down the series of this sequence
3) find the 26th term of this sequence
4) write down the nth term of this sequence
5) find the sum of the first 23 terms of this sequence

Answer 1

Answer:

1. AP

2.-17,-24

3. -171

4.-1679

Answer 2

Step-by-step explanation:

1. AP. Common Difference = -7

2. 4, -3 , -10 , -17 , -24....

3. 26th term = 4 - (7×26) = -178 ( See question 4 )

4. d= -7, f = 4

nth term = 4 + ( -7 × n )

= 4 - ( 7n )

5. S23 = [ n/2 ( 2f + ( n - 1 ) d ) ]

= [ 23/2 ( 2×4 + ( 23-1 ) -7 ]

= [ 23/2 ( 8 - 154 ) ]

= - 1679