Josh graphs a system of equations to determine the roots of the polynomial equation [tex]x^5 - 2x^2[/tex]. From the graph, he determines that there are two solutions to the equation.

Which statement is true?
A. He is correct because the graph shows two intersection points.
B. He is incorrect because the graph should show more intersection points.
C. He is incorrect because the polynomial degree suggests more possible roots.
D. He is correct because polynomial equations can have fewer solutions than their degree suggests.



Answer :

Sure, let's work through the polynomial equation step-by-step.

Firstly, the polynomial given to us is:

[tex]\[ f(x) = x^5 - 2x^2 \][/tex]

To find the roots of this polynomial, we need to set the equation equal to zero and solve for [tex]\( x \)[/tex]:

[tex]\[ x^5 - 2x^2 = 0 \][/tex]

Next, we factor the polynomial. Notice that both terms on the left-hand side share a common factor of [tex]\( x^2 \)[/tex]. So we can factor out [tex]\( x^2 \)[/tex] from each term:

[tex]\[ x^2 (x^3 - 2) = 0 \][/tex]

Now, we set each factor equal to zero and solve for [tex]\( x \)[/tex].

First, for the factor [tex]\( x^2 \)[/tex]:

[tex]\[ x^2 = 0 \][/tex]

Taking the square root of both sides, we get:

[tex]\[ x = 0 \][/tex]

This root has a multiplicity of 2, meaning it is counted twice as it is derived from [tex]\( x^2 \)[/tex].

Secondly, for the factor [tex]\( x^3 - 2 \)[/tex]:

[tex]\[ x^3 - 2 = 0 \][/tex]

Adding 2 to both sides, we have:

[tex]\[ x^3 = 2 \][/tex]

Taking the cube root of both sides, we get:

[tex]\[ x = 2^{1/3} \][/tex]

The cube root of 2 is approximately 1.2599210498948732.

Thus, there are indeed two distinct real solutions to the polynomial equation [tex]\( x^5 - 2x^2 = 0 \)[/tex]. They are:

1. [tex]\( x = 0 \)[/tex]
2. [tex]\( x = 2^{1/3} \)[/tex] (approximately 1.2599210498948732)

When the polynomial is graphed, these are the points where the graph intersects the x-axis. Hence, Josh is correct in stating that the graph shows two intersection points.