What is the value range of SiNx + cosx?

What is the value range of SiNx + cosx?

Please, you need to simplify first! I don't have a symbol editor here. I can only tell you
Put forward a root sign 2, and then transform it into the form of root sign 2Sin (x + y), and then get the value range from negative root sign 2 to positive root sign 2