document.write( "Question 1169011: Please help me Solve this equation on [0,360)
\n" );
document.write( "sin^3 (x) = sin(x)
\n" );
document.write( "Thank you in advance \n" );
document.write( "
Algebra.Com's Answer #793669 by Theo(13342) You can put this solution on YOUR website! your original equation is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin^3(x) = sin(x)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "divide both side of the equation by sin(x) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin^2(x) = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "take the square root of both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin(x) = plus or minus sqrt(1).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since sqrt(1) is equal to 1, this becomes;\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin(x) = plus or minus 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when sin(x) = 1, solve for x to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = arcsin(1) = 90 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when sin(x) = -1, solve for x to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = arcsin(-1) = -90 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "what you want is the equivalent angle that is greater than 0 and less then 360 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "add 360 to -90 and you get 270 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's the angle you're looking for.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "arcsin(-1) = 270 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i believe your answer will be x = 90 and 270 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the equation of sin^3(x) - sin(x) can be graphed.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to graph it, set up 4 equations.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they will be:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = sin^3(x) \n" ); document.write( "y = sin(x) \n" ); document.write( "y = 1 \n" ); document.write( "y = -1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the intersection of these 4 equations will be your solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the graph looks like this:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "note that sin^3(x) is equivalent to sin(x)^3.\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( " |