Final answer:
The vertex of a degree 4 polynomial involves more complex steps than a quadratic equation, requiring factoring or calculus if possible. For a simple quadratic equation, the vertex can be found using the formula -b/(2a) for the x-coordinate.
Step-by-step explanation:
Finding the vertex of a degree 4 polynomial is not as straightforward as finding the vertex of a quadratic function. However, if the polynomial can be factored into quadratic equations or if its derivative can be found, you may then identify the critical points which could lead you to the vertex - if it exists. A vertex in the context of a degree 4 (quartic) polynomial would be any local maxima or minima.
For quadratic equations of the form at² + bt + c = 0, finding the vertex is simpler as it is given by the formula –b/(2a) for the x-coordinate, and then substituting this into the equation to find the y-coordinate. For a quadratic equation with constants a = 4.90, b = 14.3, and c = -20.0, we apply the quadratic formula for finding the roots, and the vertex can be found using the mentioned formula for the x-coordinate.