Can someone explain me how we define the parametric set of functions because I have been confused.
For example if we have the parametric set of linear functions $f_{\theta}: \mathbb R^2 \rightarrow \mathbb R$.
That is for a given $x\in \mathbb R^2$, $f_\theta(x) = \theta_0 + \theta_1x_1 + \theta_2x_2$ right?
If we want to define the parametric set of the quadratic functions $f_\theta: \mathbb R \rightarrow \mathbb R$, How we will calculate it?
I want to learn from which term $f_\theta: \mathbb R \rightarrow \mathbb R$, I will learn how many parameters $x_i$ I will have which linear which quadratic etc. Basically can someone explain me how this terminology works.