update: for some reason posting screenshots here doesn't work, so here's the link to all relevant documents: https://imgur.com/a/RSjumVZ

Part 1 asks you to:

(a) Find the least squares equation for a simple linear regression model.

(b) Obtain the partial derivatives for beta0hat and beta1hat in a simple linear regression model.

I already have (a) and (b) (in attachments), but I need help answering (c) and part 2

Part 2 -> question: How would derivations similar to those in (a)(b)(c) look with this model which has a quadratic term? Y = beta0 + beta1*x + beta2*x^2

My final question: How would part C be answered for both a simple linear model and a model with

Hope this makes sense, any assistance would be much appreciated :)