Hybridizaton Textbook equation

[keyanabogan 2J]

In the textbook when it begins to talk about hybridization it mentions a few equations. These equations include the s-orbitals and s-orbitals. For example, some of the equations were h1=s+px+py+pz and h2=s-px-py+pz. I don't understand specifically what these equations show us about hybrid orbital or the concept behind them.

[Michael Lesgart 1H]

I assume that the equations must mean that the first hybridization for the atom has one s orbital and 3 p orbitals (hence px, py, pz). Therefore, you can conclude that the hybridization is sp3. You can also determine the hybridization of an atom by finding how many regions of electron density there are. So if an atom has four regions of electron density, the hybridization is sp3. If an atom has three regions of electron density, the hybridization would be sp2 and so on.
I hope this helped!

[Lauren_Bui_1A]

Also for the signs, in h1 the s and p orbitals all have their usual signs and their amplitudes add together to be all positive. But in h2, px and py are negative, so the resulting interference pattern is different.