document.write( "Question 1128737: Question Part
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\n" ); document.write( "Find the exact value of the expression in terms of x with the help of a reference triangle.
\n" ); document.write( "sin(cos−1(3 − x))
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Algebra.Com's Answer #745294 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
In the expression \"sin(cos-1(3 - x))\"
\n" ); document.write( "the \"cos-1\" or \"%22cos%22%5E%28-1%29\" part refers to the inverse cosine function,
\n" ); document.write( "so \"cos%5E%28-1%29%283-x%29\" is an angle \"A\" , between \"0\" and \"pi\"
\n" ); document.write( "(or between \"0%5Eo\" and \"180%5Eo\" if you want to visualize angles in degrees)
\n" ); document.write( "whose cosine is \"3-x\" .
\n" ); document.write( "Those angles would have a non-negative sine, so \"sin%28cos%5E%28-1%29%283-x%29%29%3E=0\" .
\n" ); document.write( "Using the trigonometric identity \"sin%5E2%28A%29%2Bcos%5E2%28A%29=1\" ,
\n" ); document.write( "\"sin%5E2%28cos%5E%28-1%29%283-x%29%29%2Bcos%5E2%28A%29=1\" ,
\n" ); document.write( "\"sin%5E2%28cos%5E%28-1%29%283-x%29%29=1-%283-x%29%5E2\" ,
\n" ); document.write( "\"sin%5E2%28cos%5E%28-1%29%283-x%29%29=1-%289-6x%2Bx%5E2%29\" ,
\n" ); document.write( "\"sin%5E2%28cos%5E%28-1%29%283-x%29%29=1-9%2B6x-x%5E2\" , and
\n" ); document.write( "\"sin%5E2%28cos%5E%28-1%29%283-x%29%29=-8%2B6x-x%5E2\"
\n" ); document.write( "We are looking for a non-negative result, so
\n" ); document.write( "\"sin%28cos%5E%28-1%29%283-x%29%29=highlight%28sqrt%28-8%2B6x-x%5E2%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "NOTE:
\n" ); document.write( "Of course \"cos%5E%28-1%29%283-x%29\" is not defined as a real number for all values of \"x\" .
\n" ); document.write( "It must be \"-1%3C=3-x%3C=1\" or \"2%3C=x%3C=4\" .
\n" ); document.write( "That is the domain of the function,
\n" ); document.write( "but that is probably not expected as part of the answer.
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