Question

How does the multiplicity of a zero affect the graph of the polynomial function?

Select answers from the drop-down menus to correctly complete the statements
The zeros of a ninth degree polynomial function are 1 (multiplicity of 3), 2, 4, and 6 (multiplicity of 4).
The graph of the function will cross through the x-axis at only
The graph
will only touch (be tangent to) the x-us at

the x-axis
At the zero of 2, the graph of the function will choose...

Answer 1

Explanation:

Let the equation of a polynomial is,

`y=(x-a)^2(x-b)^1(x-c)^3`

Zeroes of this polynomial are x = a, b and c.

For the root x = a, multiplicity of the root 'a' is 2 [given as the power of (x - a)]

Similarly, multiplicity of the roots b and c are 1 and 3.

Effect of multiplicity on the graph,

If the multiplicity of a root is even then the graph will touch the x-axis and if it is odd, graph will cross the x-axis.

Therefore, graph will cross x -axis at x = b and c while it will touch the x-axis for x = a.

In this question,

The given polynomial is,

`y=(x-1)^3(x-2)^1(x-4)^1(x-6)^4`

Degree of the polynomial = 3 + 1 + 1 + 4 = 9

The graph of the function will cross through the x-axis at x = 1, 2, 4 only, The graph will touch to the x-axis at 6 only.

At the zero of 2 , the graph of the function will CROSS the x-axis.