Question

f(n) = a + (n - 1) d, n belongs to N prove that A.M.
of f(1) and S(2n-1) is f(n) ​

Answer 1

f(n)=2n+3 is a linear function.

Hence f(n

1

)=f(n

2

)⇒n

1

=n

2

Here Domain is N but range is set of all odd number −{1,3}

Hence f(n) is injective or one-to-one function.