the frist term of the arithmetic sequence is 1/2 and the its common difference is 1/6 write the algebric form of the sequence At what position does the an integer appears as a term in the sequence first time what is the integer term frist appear in this sequence Is this sequence contain all natural number as the terms
Answers
Answer:
4th term, 1 , Contains all natural numbers
Step-by-step explanation:
Let the first integer be 'k' and 'nth' term be the required term.
Using aₙ = a + (n - 1)d
⇒ k = a + (n - 1)d
⇒ k = (1/2) + (n - 1)(1/6)
⇒ k = [3 + (n - 1)] / 6
⇒ k = (n + 2)/6
⇒ 6k = (n + 2)
Note that: for k to be an integer, (n + 2) must be divisible by 6.
For k = 1(smallest possible no. for +ve value of n):
⇒ 6 = n + 2
⇒ 4 = n
Integer term = a₄ = (1/2) + (4 - 1)(1/6)
= 1/2 + 1/2
= 1
To contain all the natural numbers:
⇒ General term = (n + 2)/6
⇒ Tₙ = (n + 2)/6
⇒ 6Tₙ = n + 2
⇒ 6T - 2 = n
n will always be a natural number(as required), for any value natural value of T. [based on 'n can't be fractional, 0 or -ve]
Hence, AP contains all natural numbers.
Given :-
The first term of the arithmetic sequence is 1/2 and its common difference is 1/6
To Find :-
Write the algebraic form of the sequence At what position does the integer appears as a term in the sequence first time what is the integer term first appear in this sequence Is this sequence contain all-natural number as the terms
Solution :-
We know that
(i) Algebraic form
aₙ = a + (n - 1)d
aₙ = (1/2) + (n - 1)1/6
aₙ = 1/2 + (n - 1)/6
aₙ = 3 + n - 1/6
aₙ = 2 + n/6 (i)
(ii) At what position does an integer appears as a term in the sequence first time
Let aₙ = x
x = 2 + n/6
6(x) = 2 + n
6x = 2 + n
Putting x as 1
6(1) = 2 + n
6 = 2 + n
6 - 2 = n
4 = n
Putting x as -1
6(-1) = 2 + n
-6 = 2 + n
-6 - 2 = n
-8 = n
No. of terms can't be negative. So, 4 = n
a₄ = a + (4 - 1)d
a₄ = a + 3d
a₄ = 1/2 + 3 × 1/6
a₄ = 1/2 + 3/6
a₄ = 3 + 3/6
a₄ = 6/6
a₄ = 1
(iii) Is this sequence contain all-natural number as the terms
Using 1
aₙ = a + (n - 1)d
aₙ = 2 + n/6
6(aₙ) = 2 + n
6aₙ = 2 + n
6aₙ - 2 = n
It contains all-natural number because it can't be negative number and zero. Only positive numbers are natural number. Hence, the answer is Yes.