A polynomial with integer coefficients is of the form
\(2x^4 + a_3 x^3 + a_2 x^2 + a_1 x + 1 = 0.\)
Find the number of different possible rational roots of this polynomial.
I just found this HERE
The rational root test theorem says that, if rational factors of a polynomial exist, then they are always in the form of
±(factor of last coefficient) / (factor of first coefficient)
So the rational roots could be 1, -1, 0.5, -0.5 and that is it.
It can't be all of those because the product of the roots must be +0.5 so it can't have 4 rational roots
It could definitely have no real roots, so therefore no rational roots.
So could it have 1 or 2 or 3 rational roots?
It can have 3
2(x-1)(x+1)(x+0.5)(x-1)= 0 that works
I don't know about 1 or 2
I suspect it could have 2 but not 1, not sure though.
So it can't have 4 or more. It could have 3 or 0.
I don't think it can have 1 but I am not sure. I can probably have 2.
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I expect are theorem/s that would make this nice and easy ....