document.write( "Question 1156563: \cos\theta-\sqrt{3}\sin\theta=1 \n" ); document.write( "
Algebra.Com's Answer #779296 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "Don't use that format to present the problem and make us guess what it is...!

\n" ); document.write( "\"cos%28theta%29-sqrt%283%29sin%28theta%29+=+1\"

\n" ); document.write( "In an equation involving sin(theta) and cos(theta), at some point we are almost certainly going to use sin^2+cos^2=1 to get the equation in either sine or cosine alone.

\n" ); document.write( "\"cos%28theta%29+=+1%2Bsqrt%283%29sin%28theta%29\"
\n" ); document.write( "\"cos%5E2%28theta%29+=+1%2B2sqrt%283%29sin%28theta%29%2B3sin%5E2%28theta%29\"
\n" ); document.write( "\"1-sin%5E2%28theta%29+=+1%2B2sqrt%283%29sin%28theta%29%2B3sin%5E2%28theta%29\"
\n" ); document.write( "\"0+=+4sin%5E2%28theta%29%2B2sqrt%283%29sin%28theta%29\"
\n" ); document.write( "\"0+=+sin%28theta%29%284sin%28theta%29%2B2sqrt%283%29%29\"
\n" ); document.write( "\"sin%28theta%29+=+0\" or \"sin%28theta%29+=+-sqrt%283%29%2F2\"
\n" ); document.write( "\"theta+=+0\" or \"theta+=+%284%2F3%29pi\" or \"theta+=+%285%2F3%29pi\"

\n" ); document.write( "At one point in our work we squared both sides of the equation; so we need to check for extraneous solutions.

\n" ); document.write( "theta = 0: \"cos%280%29=+1\"; \"1%2Bsqrt%283%29sin%280%29+=+1\" YES

\n" ); document.write( "theta = (4/3)pi: \"cos%28%284%2F3%29pi%29+=+-1%2F2\"; YES

\n" ); document.write( "theta = (5/3)pi: \"cos%28%285%2F3%29pi%29+=+1%2F2\"; NO

\n" ); document.write( "ANSWER: theta = 0; theta = (-4/3)pi

\n" ); document.write( "A graph of cos(theta)-sqrt(3)sin(theta)-1, showing zeros at 0 and (4/3)pi:

\n" ); document.write( "\"graph%28400%2C400%2C-pi%2F2%2C5pi%2F2%2C-4%2C2%2Ccos%28x%29-sqrt%283%29sin%28x%29-1%29\"

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