document.write( "Question 860523: I need some help figuring out the steps to solve this problem.
\n" ); document.write( "Find, to the nearest degree, the acute angle of rotation x that eliminates the xy term of -3x^2 + 3xy + 5y^2 - x + 2y - 6 = 0.
\n" ); document.write( "a-41 degrees
\n" ); document.write( "b-80
\n" ); document.write( "c-81
\n" ); document.write( "d-40
\n" ); document.write( "Thank you for your help!
\n" ); document.write( "

Algebra.Com's Answer #518465 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Find, to the nearest degree, the acute angle of rotation x that eliminates the xy term of -3x^2 + 3xy + 5y^2 - x + 2y - 6 = 0.
\n" ); document.write( "Form: Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0
\n" ); document.write( "-----
\n" ); document.write( "cot(2t) = (A-C)/B
\n" ); document.write( "cot(2t) = (-3-5)/3 = -8/3
\n" ); document.write( "tan(2t) = -3/8
\n" ); document.write( "2t = arctan(-5/8) = 170.56
\n" ); document.write( "t = 85.28 degrees
\n" ); document.write( "--------------------------------
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "a-41 degrees
\n" ); document.write( "b-80
\n" ); document.write( "c-81
\n" ); document.write( "d-40
\n" ); document.write( "
\n" ); document.write( "
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