finding an image of a linear transformation I am so confused in how its asking of finding an image of infinity. I am in my complex class and we have a test and this was part of the past midterm, I feel like if I do one all of the other ones should be the same I assume. Please give me some hints in how to solve it. Thank you
For the following fractional linear transformations, find the image of $\infty$.
a) $\displaystyle \frac{1}{z+3}$
b) $\displaystyle \frac{2z-1}{z+i}$
c) $\displaystyle \frac{2z-i}{iz+i}$
d) $\displaystyle \frac{2z-5}{i-3}$
Thank you so much

Hint, if $a$ is a finite, non null complex number: 
$$a / \infty = 0$$
$$a \cdot \infty = \infty$$
$$a + \infty = \infty$$
$$- \infty = \infty$$
For cases like $\frac{a \cdot z + b}{c \cdot z + d}$, where $a$ and $c$ are not null, you can take the limit, and it's $a/c$.
