Domain are all the possible x values of a function. When you look at a cosine graph you can see that it goes on into infinity in the x or horizontal direction. This means that all x values are included in cosine. Because of this the domain is:
all real numbers
or
(-∞,∞)
^^^ It can be written both ways
Hope this helped! Let me know if there is anything else I can do!
Answer:
bueh
Step-by-step explanation: