Let 
and 
be two roots of the equation x2+2x+2=0, then 
15 +
15 is equal to:
a.
512
b.
−512
c.
−256
d.
256
and be two roots of the equation x2+2x+2=0, then 15 +15 is equal to:a.
512
b.
−512
c.
−256
d.
256
Question ID - 56520 | SaraNextGen Top Answer Let and be two roots of the equation x2+2x+2=0, then 15 +15 is equal to:
a.
512
b.
−512
c.
−256
d.
256
Let and be two roots of the equation x2+2x+2=0, then 15 +15 is equal to:
|
a. |
512 |
b. |
−512 |
|
c. |
−256 |
d. |
256 |
1 Answer
127 votes
Answer Key / Explanation : (c) -
(x+1)2+1=0
(x+1)2 −(i)2=0
(x+1+i)(x+1−i)=0
∴ X=− 
So, 
15+
15=(
2)7 
+(
2)7
=−128(−i+1+i+1)
= −256
127 votes
Answer Link
127