how to solve polynomial inequalities?
well i have this example
2x^3 - 15x < x^2
and i do know i have to get 0 on one side
2x^3 - 15x - x^2 <0
how do i factor it out? can i use the quadratic formula?
that's exactly what i did , i wasn't sure if it was right though,
- TheSicilianSageLv 71 decade agoFavorite Answer
One more step:
Examine the curve: 2x^3 - 15x - x^2
And you'll see that the only time that the curve is negative is:
x < - 5/2 ... and ... 0 < x < 3 ← your factors.
So the final answer is: x < - 5/2 and 0 < x < 3
- 1 decade ago
ok that's a great start! so factor out an x:
x (2x^2- x -15)
This factors into: x (2x+5) (x-3)