Question
Mathematics Question on Functions
The number of functions f:1,2,3,4→a∈:Z∣a∣≤8 satisfying f(n)+n1f(n+1)=1,∀n∈1,2,3 is
A
2
B
1
C
4
D
3
Answer
2
Explanation
Solution
The correct answer is (A) : 2
f:1,2,3,4→a∈Z:∣a∣≤8
f(n)+21(n+1)=1,∀n∈1,2,3
f(n+1) must be divisible by n
f(4)⇒−6,−3,0,3,6
f(3)⇒−8,−6,−4,−2,0,2,4,6,8
f(2)⇒−8,……⋯⋯⋯,8
f(1)⇒−8,…………….8
3f(4) must be odd since f(3) should be even therefore 2 solution possible.
f(4) | f(3) | f(2) | f(1) |
---|---|---|---|
-3 | 2 | 0 | 1 |
3 | 0 | 1 | 0 |