document.write( "Question 539229: Find the magnitude and direction (in degrees) of the vector.
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document.write( "v = 3i +√7j \n" );
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Algebra.Com's Answer #353359 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! If v = ai+bj, then ||v|| = sqrt(a^2+b^2)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "In this case, a = 3 and b = sqrt(7)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "||v|| = sqrt(a^2+b^2)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "||v|| = sqrt(3^2+(sqrt(7))^2)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "||v|| = sqrt(9+7)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "||v|| = sqrt(16)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "||v|| = 4\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the magnitude of v is 4\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "To find the direction or angle, we use the idea that theta = arctan(b/a)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "theta = arctan(b/a)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "theta = arctan(sqrt(7)/3)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "theta = 41.409622 (note: this is approximate)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the direction is roughly 41.409622 degrees. \n" ); document.write( " \n" ); document.write( " |