Question

If f(1) = 10 and f(n) = f(n = 1) – 4 then find the value of f(5).

Answer 1

Given:

`f(1)=10` and
`f(n)=f(n-1)-4`.

To find:

The value of f(5).

Solution:

We have,

`f(n)=f(n-1)-4`

For
`n=2`,

`f(2)=f(2-1)-4`

`f(2)=f(1)-4`

`f(2)=10-4`

`f(2)=6`

For
`n=3`,

`f(3)=f(3-1)-4`

`f(3)=f(2)-4`

`f(3)=6-4`

`f(3)=2`

For
`n=4`,

`f(4)=f(4-1)-4`

`f(4)=f(3)-4`

`f(4)=2-4`

`f(4)=-2`

For
`n=5`,

`f(5)=f(5-1)-4`

`f(5)=f(4)-4`

`f(5)=-2-4`

`f(5)=-6`

Therefore, the value of
`f(5)` is
`-6`.