I am asked to prove a 4th degree polynomial:
p(x) = x^4+x^3-3
Has at least 2 roots...
And that some other equation doesn't roots in interval (-oo,-2)
and that it has 3 roots in (-oo,+oo)
what does it means that an equation has roots? or to find it?
like with the quadratic formula that you find the +- x's ? (is has either 1 or 2 right?)
Is there a simple way to find roots of such equations (with x^3 or higher degree)?