document.write( "Question 551151: If a = 2i - 2j - k and b = -4i + 3j - 2k\r
\n" ); document.write( "\n" ); document.write( "a) find the angle between the vectors
\n" ); document.write( "b) find the vector product. \n" ); document.write( "
Algebra.Com's Answer #359452 by Alan3354(69443)\"\" \"About 
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If a = 2i - 2j - k and b = -4i + 3j - 2k\r
\n" ); document.write( "\n" ); document.write( "a) find the angle between the vectors
\n" ); document.write( "b) find the vector product.
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\n" ); document.write( "a)
\n" ); document.write( "|a| = sqrt(2^2 + 2^2 + 1) = 3
\n" ); document.write( "|b| = sqrt(4^2 + 3^2 + 2^2) = sqrt(29)\r
\n" ); document.write( "\n" ); document.write( "Dot product = 2*-4 + -2*3 + -1*-2 = -12
\n" ); document.write( "a dot b = |a|*|b|*cos(angle)
\n" ); document.write( "-12 = 3sqrt(29)*cos(A)
\n" ); document.write( "cos(A) = -12/3sqrt(29)
\n" ); document.write( "A =~ 137.97 degs
\n" ); document.write( "----------------
\n" ); document.write( "b)
\n" ); document.write( "|+i +j +k|
\n" ); document.write( "|+2 -2 -1| = a X b
\n" ); document.write( "|-4 +3 -2|\r
\n" ); document.write( "\n" ); document.write( "= i*(4 + 3) - j*(-4 - 4) + k*(6 - 8)
\n" ); document.write( "= 7i + 8j + 2k
\n" ); document.write( " \n" ); document.write( "
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