What does $cos (arctan (- 4)) + sin (arccos (9))$ $cos(arctan(-4))+sin(arccos(9))$ equal?

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Answer 1 · 2016-04-09T17:00:02

arc cos 9 is unreal.

If a = arc cos 9, cos a = 9. As $| cos a | \leq 1$ $|cos a|<=1$ , the value 9 is inadmissible.

What does cos(arctan(−4))+sin(arccos(9))cos(arctan(-4))+sin(arccos(9)) equal?