Where did I go wrong on this problem, Find the exact value of the expression cos^-1[cos(4PI/3)] cos of 4PI/3 =-1/2 cos^-1 of (-1/2)= 2PI/3 or 2.094395102
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Last edited by stapel; Apr 11th 2009 at 12:54 PM. Reason: Better reply follows. Thank you, skeeter!
Originally Posted by cross1933 Where did I go wrong on this problem, Find the exact value of the expression cos^-1[cos(4PI/3)] cos of 4PI/3 =-1/2 cos^-1 of (-1/2)= 2PI/3 or 2.094395102 who said it was wrong? because ... the range of the inverse cosine function is
Originally Posted by skeeter who said it was wrong? because ... the range of the inverse cosine function is is not one of the answer choices, that is what is confusing me.
Originally Posted by stapel Domain 1,-1 Range 0,
Originally Posted by cross1933 is not one of the answer choices, that is what is confusing me. don't know what to tell you ... but, I know my solution is correct.
Originally Posted by skeeter don't know what to tell you ... but, I know my solution is correct. Not sure what I will do, maybe I will email one of the class members. Thanks
for the record, what are the answer "choices" ?
Originally Posted by skeeter for the record, what are the answer "choices" ? 1/2 -1/2
Originally Posted by cross1933 1/2 -1/2 None of those options are correct. The answer given by you and skeeter is the correct answer.
Is it possible the cos^-1 and the cos cancel leaving the answer as ?
Originally Posted by cross1933 Is it possible the cos^-1 and the cos cancel leaving the answer as ? You know that does not lie in the range of , so it cannot be the correct answer. (However, whoever wrote the question might not realise this .....)
Originally Posted by mr fantastic You know that does not lie in the range of , so it cannot be the correct answer. (However, whoever wrote the question might not realise this .....) That is true, still hoping I overlooked something simple. The author of the question may not be aware of this?
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