What is the end behavior of the graph of f(x) = x5 - 8x4 + 16x3?
Solution:
Given, f(x) = x5 - 8x4 + 16x3
We have to find the end behavior of the graph.
1) As x approaches -∞, x5 will also approach -∞. This is because when we raise a negative number to the power of an odd number, the result remains negative.
2) As x approaches +∞, x5 will also approach +∞. This is because when we raise a positive number to the power of an odd number, the result remains positive.
3) Finding the roots of the given function,
f(x) = x5 - 8x4 + 16x3
Taking x3 as common,
x3(x2 - 8x + 16) = 0
x3(x2 - 4x - 4x + 16) = 0
x3(x(x - 4) - 4(x - 4)) = 0
x3(x - 4)(x - 4) = 0
x3 = 0
So, x = 0
x - 4 = 0
x = 4
So, the roots are x = 0, and x = 4.
This implies that the graph has a repeated root and so it will touch the x-axis but not at the repeated root of x = 4.
4) Since 0 is a root and it does not cross at x = 4, the graph will cross at x = 0.
Therefore, the graph does not cross the x-axis at x = 4 but crosses the x-axis at x = 0.
What is the end behavior of the graph of f(x) = x5 - 8x4 + 16x3?
Summary:
The end behavior of the graph of f(x) = x5 - 8x4 + 16x3 is that as x → -∞, x5 → -∞ and as x → ∞, x5 → ∞ and the graph does not cross the x-axis at x = 4 but crosses the x-axis at x = 0.
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