SOLUTION: Which of the statement most accurately portrays the domain of the functions cosine and arccos? A.) Cosine domain consists of all real numbers; arccos domain is also all real num

Algebra ->  Test -> SOLUTION: Which of the statement most accurately portrays the domain of the functions cosine and arccos? A.) Cosine domain consists of all real numbers; arccos domain is also all real num      Log On


   

Question 1062064: Which of the statement most accurately portrays the domain of the functions cosine and arccos?
A.) Cosine domain consists of all real numbers; arccos domain is also all real numbers.
B.) Cosine domain is restricted; arccos domain consists of all real numbers.
C.) Cosine domain consists of all real numbers; arccos domain is restricted.
D.) Cosine domain is restricted; arccos domain also restricted.
Answer by math_helper(2461) About Me  (Show Source):
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Domain is the set of possible values that can be input into a function.
For cos(x), x can be any real value (this is true because angles can go around and around and even land on top of each other, for example a rotation of 50 degrees and a rotation of 410 degrees lands at the same angle from the positive x-axis). So, cos(x) domain is unrestricted.
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For arccos(x), there is a restriction that +-1+%3C=+x+%3C=+1 because "cos(x)" always produces a number between -1 and +1 inclusive. Thus, arccos() domain is restricted.
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So answer C looks right.