Question

The graph of the function f (x)=3x^3+5x^2-3x-15 is shown below. Choose the best description of the roots.Two real root and one non-real roots.Three real roots.Three non-real roots.One real root and two non-real roots.

Answer 1

The roots of a function are the values at which the function is equal to "0". This is usually seen when the graph of the function crosses the x-axis. These values are the real roots.

A third order polinomyal always has three roots. This means that if the graph only crosses the "x-axis" once, then one root is real, while the others are complex. On this case the graph crosses the x-axis once, so there is one real root and two non-real roots.