Answer :
Answer: The all possible rational roots are [tex]x=\pm1,\pm2,\pm3,\pm4,\pm6,\pm12,\pm\frac{1}{2},\pm\frac{3}{2},\pm\frac{1}{4},\pm\frac{3}{4},\pm\frac{1}{10},\pm\frac{1}{5},\pm\frac{3}{5}\pm\frac{3}{10},\pm\frac{2}{5},\pm\frac{6}{5},\pm\frac{1}{20},\pm\frac{3}{20},\pm\frac{4}{5},\pm\frac{12}{5}[/tex].
Explanation:
The given polynomial is,
[tex]f(x)=20x^4+x^3+8x^2+x-12[/tex]
The Rational Root Theorem states that the all possible roots of a polynomial are in the form of a rational number,
[tex]x=\frac{p}{q}[/tex]
Where p is a factor of constant term and q is the factor of coefficient of leading term.
In the given polynomial the constant is -12 and the leading coefficient is 20.
All possible factor of -12 are [tex]\pm1,\pm2,\pm3,\pm4,\pm6,\pm12[/tex].
All possible factor of 20 are [tex]\pm1,\pm2,\pm4,\pm5,\pm10,\pm20[/tex].
So, the all possible rational roots of the given polynomial are,
[tex]x=\pm1,\pm2,\pm3,\pm4,\pm6,\pm12,\pm\frac{1}{2},\pm\frac{3}{2},\pm\frac{1}{4},\pm\frac{3}{4},\pm\frac{1}{10},\pm\frac{1}{5},\pm\frac{3}{5}\pm\frac{3}{10},\pm\frac{2}{5},\pm\frac{6}{5},\pm\frac{1}{20},\pm\frac{3}{20},\pm\frac{4}{5},\pm\frac{12}{5}[/tex]