I'm starting to learn proof and logic, all my knowledge in mathematics is: basic discrete boolean logic, introductory logic, basic Calculus, Introductory Linear Algebra.
I've been trying to use what I know to prove this statement, but I simply can't.
If $x$ is real number such that $x^4 + 2x^2 -2x \lt 0$, then $0\lt x\lt 1$.
I dont know enough Calculus to find its roots, and if use Newton's method, I am able to find $x=0$ and $x\approx 0.77777$. But I wont know if there are two more real roots.
Any tips?