The product of all possible values of , for which x 0 ( 1- ( x) (( +1)x) (( +2)x) 2(( +1)x) )=2, is :
- -2
- 1
- -1
- 54
Answer
(3) -1
Solution
For small x: (kx)=1- k2x22+O (x4 )
( x) (( +1)x) (( +2)x)=1- [ 2+( +1)2+( +2)2 ]x22+O (x4 )
and 2(( +1)x)=( +1)2x2+O (x4 )
Limit = 2+( +1)2+( +2)22( +1)2=2 ( -1)
3 2+6 +5=4 2+8 +4
2+2 -1=0 (real, distinct roots -1 2, neither equal to -1)
Product of all values of =-1
Answer: (3)