document.write( "Question 1011207: Find a vector perpendicular to the given vector 2i+9j-6k
\n" );
document.write( "Please Show all your work step by step. \n" );
document.write( "
Algebra.Com's Answer #626783 by mathmate(429)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Question: \n" ); document.write( "Find a vector perpendicular to the given vector 2i+9j-6k \n" ); document.write( "Please Show all your work step by step. \n" ); document.write( " \n" ); document.write( "Solution: \n" ); document.write( "A vector will be denoted \n" ); document.write( "We're looking for a vector perpendicular to P=<2,9,-6>. \n" ); document.write( "In fact, there is an infinite number of vectors perpendicular to P. \n" ); document.write( "We know that the cross product of two non-parallel vectors P, Q is perpendicular to both P and Q. \n" ); document.write( "So by finding the cross product P and an arbitrary vector Q=, we can obtain the vector R=PxQ such that R is perpendicular to both P and Q, with the restriction that Q is not parallel to P, or Q does not equal kQ where k is a real number. \n" ); document.write( "The cross product can be obtained by evaluation of the determinant \n" ); document.write( "|i j k | \n" ); document.write( "|2 9 -6| \n" ); document.write( "|a b c | \n" ); document.write( "which gives R=<9c+6b, -2c-6a, 2b-9a> \n" ); document.write( "Thus \n" ); document.write( "R=<9c+6b, -2c-6a, 2b-9a> is a vector perpendicular to P=<2,9,-6> for any vector Q= such that Q≠kP and k is a real number. |