There is a bump because of imaginary roots. Try factoring the original polynomial into a product of quadratics and then solve each quadratic.
Hi. X^4-3x^2-4 I got the intercepts just fine 2,0 -2,0 0,-4 And the ends both face up on the graph. I'm confused on how they connect to 0,-4 because there is a little upwards bump in between. How do I know if there's a bump or not? We don't need to know how high the bump goes we just need to signify there is one.Thanks