document.write( "Question 1098979: Find all solutions if 0° ≤ θ < 360°. When necessary, round your answers to the nearest tenth of a degree. (Enter your answers as a comma-separated list.)
\n" ); document.write( "sin^2 2θ − 5 sin 2θ − 1 = 0 \n" ); document.write( "

Algebra.Com's Answer #713517 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
Use a substitution,
\n" ); document.write( " $\"u=sin%282%2Atheta%29\"$
\n" ); document.write( "Then,
\n" ); document.write( " $\"u%5E2-5u-1=0\"$
\n" ); document.write( "Complete the square,
\n" ); document.write( " $\"u%5E2-5u%2B%285%2F2%29%5E2-1=%285%2F2%29%5E2\"$
\n" ); document.write( " $\"%28u%2B5%2F2%29%5E2=25%2F4%2B4%2F4\"$
\n" ); document.write( " $\"%28u%2B5%2F2%29%5E2=29%2F4\"$
\n" ); document.write( " $\"u%2B5%2F2=0+%2B-+sqrt%2829%29%2F2\"$
\n" ); document.write( " $\"u=-5%2F2+%2B-+sqrt%2829%29%2F2\"$
\n" ); document.write( "Only one solution is valid since $\"-5%2F2-sqrt%2829%2F2%29%3C-1\"$ .
\n" ); document.write( " $\"sin%282%2Atheta%29=-5%2F2%2Bsqrt%2829%29%2F2\"$
\n" ); document.write( " $\"sin%282%2Atheta%29=-0.19258\"$
\n" ); document.write( "Two solutions,
\n" ); document.write( " $\"theta=95.6\"$ and
\n" ); document.write( " $\"theta=174.5\"$ \n" ); document.write( "

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