Showing posts with label .... (1 mark). Show all posts
Showing posts with label .... (1 mark). Show all posts

1, 4, 7, 10, .... (1 mark)

(iii) 1, 4, 7, 10, .... (1 mark)

Sol. t1 = 1, t2 = 4, t3 = 7, t4 = 10

t2 – t1 = 4 – 1 = 3
t3 – t2 = 7 – 4 = 3
t4 – t3 = 10 – 7 = 3

Here, The difference between ANY two consecutive terms 3 which is constant.


∴ The sequence is an A.P.

(vii) 2, 5, 8, 11, .... (1 mark)

(vii) 2, 5, 8, 11, .... (1 mark)
Sol. t1 = 2
t2 = 2 + 3 = 5
t3 = 5 + 3 = 8
t4 = 8 + 3 = 11
t5 = 11 + 3 = 14
t6 = 14 + 3 = 17
t7 = 17 + 3 = 20
t8 = 20 + 3 = 23

∴ The next four terms of the sequence are 14, 17, 20 and 23.

(vi) 0.1, 0.01, 0.001, 0.0001, .... (1 mark)

(vi) 0.1, 0.01, 0.001, 0.0001, .... (1 mark)

Sol. t1 = 0.1
t2 = 0.1 × 0.1 = 0.01
t3 = 0.01 × 0.1 = 0.001
t4 = 0.001 × 0.1 = 0.0001
t5 = 0.0001 × 0.1 = 0.00001
t6 = 0.00001 × 0.1 = 0.000001
t7 = 0.000001 × 0.1 = 0.0000001

t8 = 0.0000001 × 0.1 = 0.00000001


The next four terms of the sequence are 0.00001, 0.000001,

0.0000001 and 0.00000001.

(iv) 192, – 96, 48, – 24, .... (1 mark)

(iv) 192, – 96, 48, – 24, .... (1 mark)

Sol. t1 = 192

t2 = 192 / –2 = – 96

t3 = –96 / – 2 = 48

t4 = 48 / – 2 = – 24

t5 = –24 / – 2 = 12

t6 = 12 / – 2 = – 6

t7 = – 6 / – 2 = 3

t8 = 3/ – 2 = 3/ – 2


∴  The next four terms of the sequence are 12, – 6, 3 and 3/–2

(iii) 1, 3, 7, 15, 31, .... (1 mark)

(iii) 1, 3, 7, 15, 31, .... (1 mark)

Sol. t1 = 1
t2 = t1 + 2 = 1+ 2 = 3
t3 = t2 + 4 = 3 + 4 = 7
t4 = t3 + 8 = 7 + 8 = 15
t5 = t4 + 16  = 15 + 16 = 31
t6 = t5 + 32  = 31 + 32 = 63
t7 = t6  + 64  = 63 + 64 = 127
t8 = t7  + 128  = 127 + 128 = 255
t9 = t8  + 256  = 255 + 256 = 511

∴ The next four terms of the sequence are 63, 127, 255 and 511.