Answer:
Solving the equation using quadratic formula we get [tex]\mathbf{x=0.119\:or\:x=-2.785}[/tex]
Step-by-step explanation:
We need to use the quadratic formula to find the solutions for
[tex]y = 3x^2 + 8x - 1[/tex]
(Note: quadratic formula is used when x^2 is in the equation. So considering 3x^2 instead of 3x^3)
The quadratic formula is: [tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
From the given equation [tex]y = 3x^3 + 8x - 1[/tex] we have a =3, b=8 and c =-1
Putting values in the formula and finding solutions:
[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\\x=\frac{-8\pm\sqrt{(8)^2-4(3)(-1)}}{2(3)}\\x=\frac{-8\pm\sqrt{64+12}}{6}\\x=\frac{-8\pm\sqrt{76}}{6}\\x=\frac{-8\pm8.71}{6}\\x=\frac{-8+8.71}{6}\:or\:x=\frac{-8-8.71}{6}\\x=0.119\:or\:x=-2.785[/tex]
So, Solving the equation using quadratic formula we get [tex]\mathbf{x=0.119\:or\:x=-2.785}[/tex]
