Answer:
Option (4)
Step-by-step explanation:
Option (1)
f(x) = 4x⁴- 7x²+ x + 25
Possible rational roots will be,
[tex]\frac{\pm \text{Factors of constant term '25'}}{{\pm \text{Factors of leading coefficient '4'}}}[/tex]
For the given function,
Possible rational roots = [tex]\frac{\pm 1, 5, 25}{\pm 1,2}[/tex]
= [tex]\pm 1, \pm 5, \pm 25, \pm \frac{1}{2},\pm\frac{5}{2},\pm\frac{25}{2}[/tex]
Therefore, [tex]-\frac{2}{5}[/tex] is not the possible root.
Option (2)
f(x) = 9x⁴- 7x²+ x + 10
Possible rational roots = [tex]\frac{\pm 1,\pm 2,\pm 5,\pm10}{\pm 1,\pm3,\pm9}[/tex]
Therefore, [tex]-\frac{2}{5}[/tex] is not the possible root.
Option (3)
f(x) = 10x⁴- 7x²+ x + 9
Possible rational roots = [tex]\frac{\pm1, \pm3, \pm9}{\pm 1,\pm2,\pm5,\pm10}[/tex]
Therefore, [tex]-\frac{2}{5}[/tex] is not the possible root.
Option (4)
f(x) = 25x⁴- 7x²+ x + 4
Possible rational roots = [tex]\frac{\pm 1,\pm2,\pm5}{\pm1,\pm5,\pm 25}[/tex]
= [tex]\pm1,\pm2,\pm5,\pm\frac{1}{5},\pm\frac{1}{25},\pm\frac{2}{5},\pm\frac{2}{25}[/tex]
Therefore, [tex]-\frac{2}{5}[/tex] is the possible rational root.
Option (4) will be the answer.
