Hello, I'm currently doing vectors in class, but I don't know what these parts mean. Especially φ(a,b). I understand cos(φ), but I don't understand cos(φ(a,b)). φ is the angle between two vectors a and b, but what does the (a,b) part add? I tried to google, but I couldn't really find anything helpful. Again, I'm not interested in proof or anything of the likes right now. For now I am just trying to decipher the symbols so I understand what I am doing. Thanks in advance for the help.