To understand the end behavior of the polynomial function f(x) = x5 – 9x4 + 18x3, we need to focus on its leading term, which is x5.
The leading term of a polynomial largely dictates its behavior as x approaches positive and negative infinity. In this case:
- As x → +∞ (x approaches positive infinity):
- The leading term x5 will dominate. Since x5 approaches +∞, we can conclude that:
f(x) → +∞
- As x → -∞ (x approaches negative infinity):
- The leading term x5 will also dominate. However, since we are dealing with an odd power, x5 approaches -∞. Thus, we have:
f(x) → -∞
In summary, the end behavior of the graph of the given polynomial function is:
- As x approaches positive infinity, f(x) approaches positive infinity.
- As x approaches negative infinity, f(x) approaches negative infinity.
This means that the graph will rise to the right and fall to the left, characteristic of polynomial functions with an odd degree and a positive leading coefficient.