ANSWER
d. The set of all real numbers
EXPLANATION
The basic cosine function ,

is continuous everywhere.
The function is defined for all real values of x.
The domain is the set all values of x that will make the function defined.
The domain is all real numbers.
The correct choice is D.
Answer:
4.5
Step-by-step explanation:
90 minutes or 1 hour and 30 minutes.
Hope this helps,
kwrob
The answer is D because both of those answer choices can be proved by looking at the triangle