Question

1) Check the list of numbers defined by the nth term 5 + 6n is an A.P or not .​

Answer 1

Answer:

5+6n

→5+6(1)=5+6=11

→5+6(2)=5+12=17

→5+6(3)=5+18=23

→5+6(4)=5+24=29.........

11,17,23,29,..............

a=11,

d=17-11=6

=23-17=6

so they are in AP.

Answer 2

Assume that n=1

5+6n = 5+6(1)

=5+6 = 11

Assume that n=2

5+6n = 5+ 6(2)

=5+12 =17

Assume that n=3

5+6n = 5+6(3)

= 5+18 = 23

11,17,23

d = a2 - a1, a3 - a2,

= 17 - 11, 23 - 17

= 6 , 6

Therefore the terms are in AP