What is the end behavior of the function f(x) = x^3 + 2x^2 + 4x + 5?

1 Answer
Aug 21, 2015

The end behaviour of a polynomial function is determined by the term of highest degree, in this case x^3.

Hence f(x)->+oo as x->+oo and f(x)->-oo as x->-oo.

Explanation:

For large values of x, the term of highest degree will be much larger than the other terms, which can effectively be ignored. Since the coefficient of x^3 is positive and its degree is odd, the end behaviour is f(x)->+oo as x->+oo and f(x)->-oo as x->-oo.