f(x) = x³ + 2x² + 4x + 5
The dominate term is x^3
As x^3 goes to negative infinity
f(-inf) =( - inf) ^3 = - inf
We know that it goes to - infinity
As x^3 goes to infinity
f(inf) =( inf) ^3 = inf
We know that it goes to infinity
It is down on the left and up on the right
