Tip:A–D to answerE for explanationV for videoS to reveal answer
If the real number x when added to its inverse gives the minimum value of the sum, then the value of x is equal to:
- A.
-2
- B.
2
- C.
1
(Correct Answer) - D.
-1
Explanation
Let the sum be:
For minimum value, differentiate and equate to zero:
Checking for minimum (using second derivative):
At x=1:
\frac{2}{(1)^3} = 2 > 0 \text{ (Minimum)}
At x=−1:
\frac{2}{(-1)^3} = -2 < 0 \text{ (Maximum)}
Correct Option: (c)
Explanation
Let the sum be:
For minimum value, differentiate and equate to zero:
Checking for minimum (using second derivative):
At x=1:
\frac{2}{(1)^3} = 2 > 0 \text{ (Minimum)}
At x=−1:
\frac{2}{(-1)^3} = -2 < 0 \text{ (Maximum)}
Correct Option: (c)
