Let f:R-\0\ be a function such that f(x)-6f ( 1x )= 353x- 52. If x 0 ( 1 x+f(x) )= ; , , then +2 is equal to
- 6
- 5
- 3
- 4
Answer
(4) 4
Solution
Replace x 1x and solve the pair:
f(x)-6f ( 1x )= 353x- 52, f ( 1x )-6f(x)= 35x3- 52
-35f(x)= 353x+70x- 352 f(x)=- 13x-2x+ 12
Finite limit as x 0 1 = 13, so =3, = 12
+2 =4
Answer: (4)