document.write( "Question 77922: find all solutions for equation with value of x between 0 and 360 degrees:
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document.write( "1. sin(4x) + sin x = 0
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document.write( "I have 2(2sin(x) cos (x))(cox(2x)) + sin x = 0
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document.write( "so far but don't know which identity to use for cos(2x) that will help solve.\r
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document.write( "This is from my daughter's textbook but I don't have the book with me now. She's taking pre-calc in high school. Thanks \n" );
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Algebra.Com's Answer #55857 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since we know the value of x for \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let \n" ); document.write( "\n" ); document.write( "So we get\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now set each factor equal to zero. Lets start with \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now let \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use the quadratic formula to solve for y\r \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So if we replace y with \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Take the arccosine of both sides (for the solution \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now lets use the other answer of \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Take the arccosine of both sides\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-----------------------------------------------------------------------------\r \n" ); document.write( "\n" ); document.write( "So after all of that, we find that our solutions are\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As always, we can check our work by using a calculator.\r \n" ); document.write( "\n" ); document.write( "This is a lot to take in, so feel free to ask me further about any of this. \n" ); document.write( " |