Infinite Limit Complex Function

[rmcclurk]

Homework Statement

Find the limit of a complex number involving infinity.

Homework Equations

Lim z->infiity of (8z^3+5z+2)

The Attempt at a Solution

I tried to split the problem into real and imaginary parts using z = x+iy, but I don't know how to deal with the z->infinity.

Thanks!

 

[nickjer]

I could be misreading the problem, but the real part and imaginary part of that equation will go to infinity as well no matter which you take.

 

[Dick]

z->infinity means |z|->infinity. What can you say about lim |8z^3+5z+2|?

 

[HallsofIvy]

Thanks, Dick. I was about to ask exactly what "z-> infinity" meant! In the complex plane there can be an infinite number of "infinities"!