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harsh.champ
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The number of non-negative real roots of 2^x - x - 1 = 0 equals
(A)0
(B)1
(C)2
(D)3
(E)4
The OA is C.
For reference,here is the soln.[spoiler]
2^x - x - 1 = 0
2^x - 1 = x
If we put x = 0, then this is satisfied and we put x = 1, then this is also satisfied.
Now we put x = 2, then this is not valid.[/spoiler]
(A)0
(B)1
(C)2
(D)3
(E)4
The OA is C.
For reference,here is the soln.[spoiler]
2^x - x - 1 = 0
2^x - 1 = x
If we put x = 0, then this is satisfied and we put x = 1, then this is also satisfied.
Now we put x = 2, then this is not valid.[/spoiler]
Last edited by harsh.champ on Tue Feb 09, 2010 4:28 am, edited 1 time in total.
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