what is (a + b)^2 for a = 1 and b = cos?

:/
(1+x)^2 is 1+2x+xx
(1+cos )^2 is 1+2cos+coscos

sorry guys fell asleep. literally my brain is just out of commission, i get it now. gonna come back to all this tomorrow, i cant comprehend this crap anymore if im forgetting to foil lol. thanks a lot man

Not to confuse the OP or anthing, but I am curious:

Why doesn't it have three solutions: pi/2, 3pi/2, and pi.

I am getting 2cosx(1+cosx)=0

2cosx=0 --> pi/2 and 3pi/2
1=cosx=0 --> pi

I understand I am wrong because of the graph, but I don't understand why.

pretty sure it has to do with the principal domain cosine is defined on