finding fix points of Möbius transformation

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I need to find the fixed points of the following:

dilation on $\mathbb{C}_{\infty}$
translation on $\mathbb{C}_{\infty}$
inversion on $\mathbb{C}_{\infty}$

I'm thinking using Möbius transformations, I know $S(z) = z$ would be a fixed point for a Möbius transformation $S$, and $S(z) = za$ would be a dilation on it, with $z,a \in \mathbb{C}$.

We know $S(z) = z$ gives a fixed point.

Suppose $S(z) = az$ is a dilation with $a \neq 1$, then we can see only $z = 0$ and $z = \infty$ are points mapped to themselves.

Suppose $S(z) = z + a$ is a translation with $a \neq 0$, then we can see only $z = \infty$ is mapped to itself.

Suppose $S(z) = \frac{1}{z}$ is an inversion, then we can see only $z = 1$ is mapped to itself.

Am I on the right track?