Which of the functions graphed below could be defined by a cubic equation?

The correct option is 3.

Step-by-step explanation:

If a polynomial has degree n, then the number of zeros of the polynomial is n and number of turns in (n-1).

The degree of a cubic function is 3, it means the number of zeros is 3 and number of turns is 2.

Since the cubic function has 3 zeros, therefore the graph of cubic function intersect the x-axis at three points.

From the given graph it is noticed that the first graph has two x-intercepts and one turn, therefore it represent a quadratic function.

The second graph has four x-intercepts and three turns, therefore it represents a quartic function.

The third graph has three x-intercepts and two turns, therefore it represents a cubic function. So option 3 is correct.

The fourth graph has five x-intercepts and 4 turns, therefore the degree of the function is 5.

answer: 1 + 1 = 11

step-by-step explanation: