Question

What are the possible numbers of positive, negative, and complex zeros of f(x) = −3x4 + 5x3 − x2 + 8x + 4?

Answer 1

Judging from the graph (attached), there is one negative and one positive zero. Since this is a 4-th order polynomial, it has 4 zeros in total. So there are 2 complex zeros with imaginary components.