High School

What is the [tex]y[/tex]-intercept of the graph [tex]y = -x^6 - 6x^5 + 50x^3 + 45x^2 - 108x - 108[/tex]?

A. [tex](0, -3)[/tex]
B. [tex](0, -108)[/tex]
C. [tex](2, 0)[/tex]
D. There is no [tex]y[/tex]-intercept.

Answer :

To find the y-intercept of a graph, you need to determine the value of [tex]\( y \)[/tex] when [tex]\( x \)[/tex] is equal to 0. The y-intercept is the point where the graph crosses the y-axis.

Let's find the y-intercept for the polynomial:

[tex]\[ y = -x^6 - 6x^5 + 50x^3 + 45x^2 - 108x - 108. \][/tex]

1. Substitute [tex]\( x = 0 \)[/tex] into the equation:

[tex]\[ y = -0^6 - 6(0)^5 + 50(0)^3 + 45(0)^2 - 108(0) - 108. \][/tex]

2. Simplify each term:

[tex]\[
\begin{align*}
-0^6 & = 0, \\
-6(0)^5 & = 0, \\
50(0)^3 & = 0, \\
45(0)^2 & = 0, \\
-108(0) & = 0.
\end{align*}
\][/tex]

3. Add the constant term:

[tex]\[ y = 0 + 0 + 0 + 0 + 0 - 108 = -108. \][/tex]

Therefore, the y-intercept is at the point [tex]\((0, -108)\)[/tex].

The correct answer is B. [tex]\((0, -108)\)[/tex].