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The equation `x^(3) - 3x + 1 = 0` hasA. no rational but three irrational rootsB. one rational and two irrational rootsC. no real rootsD. three rational roots

Answer» Correct Answer - A
If possible, let `(p)/(q)` be a rational roots of `x^(3) - 3x + 1 = 0`. Then, p is a factor of the constant term i.e. 1 and q is a factor of coefficient of `x^(3)` i.e. 1.
`therefore" "p = +- 1 and q = +- 1 rArr (p)/(q) = 1, -1`
But, 1 and -1 do not satisfy the given equation.
Hence, the given equation has no rational roots.


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