2021 JMPSC Accuracy Problems/Problem 4
If is its own reciprocal, find the product of all possible values of
From the problem, we know that
Thus, or . Our answer is
We have , so . By Vieta's our roots and amount to
Therefore, the product of the root is
The only numbers that are their own reciprocals are and . The equation has the solution , while the equation has the solution . The answer is .
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