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Consider the equation `x^(2) + 2x - n = 0`m where `n in N` and `n in [5, 100]`. The total number of different values of n so that the given equation has integral roots isA. 8B. 3C. 6D. 4 |
Answer» Correct Answer - 1 `x^(2) + 2x - n = 0 rArr (x + 1)^(2) = n + 1` `rArr x = -1 pm sqrt(n + 1)` Thus, n + 1 should be a perfect square. Now, `n in [5, 100] rArr n + 1 in [6, 101]` Perfect square values of n + 1 are 9, 16, 25, 36, 49, 64, 81, 100. Hence, number of values is 8. |
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