5.5 Web material 79http://www.chass.utoronto.ca/~osborne/MathTutorial/QFF.HTM
http://www.chass.utoronto.ca/"osborne/MathTutorial/QFS.HTM
http://www.chass.utoronto.ca/~osborne/MathTutorial/QUF.HTM
http://www.cs.ut.ee/~toomas_l/linalg/lin2/node25.html
http://www.csie.ncu.edu.tw/~chia/Course/LinearAlgebra/sec8-2.pdf
http://www.ece.mcmaster.ca/~kiruba/3sk3/lecture7.pdf
http://www.ece.uwaterloo.ca/~ecel04/TheBook/04LinearAlgebra/
cholesky/
http://www.ee.ic.ac.uk/hp/staff/dmb/matrix/property.html
http://www.es.ucl.ac.uk/undergrad/geomaths/pdilink6.htm
http://www.iam.ubc.ca/~norris/research/quadapp.pdf
http://www.ics.mq.edu.au/"chris/mathl23/chap05.pdf
http://www.imada.sdu.dk/"swann/MM02/Quadrat icForms.pdf
http://www.imsc.res.in/~kapil/crypto/notes/node37.html
http://www.matf.bg.ac.yu/r3nm/NumericalMethods/LAESolve/
Cholesky.html
http://www.math.niu.edu/~rus in/known-math/99/posdef
http://www.math.oregonstate.edu/home/programs/undergrad/
CalculusQuestStudyGuides/vcalc/min_max/min_max.html
http://www.math.rutgers.edu/courses/251/s01bumby/slide011.ps2.pdf
http://www.math.tamu.edu/~bollingr/Notes/bzb83.pdf
http://www.math.ucla.edU/~xinweiyu/164.l.05f/1102.pdf
http://www.math.uga.edu/~ chadm/quadrat ic.pdf
http://www.math.uic.edu/math210/labs/lab5.html
http://www.math.uic.edu/~math210/newlabs/critpts/critpts.html
http://www.math.uiuc.edu/documenta/lsu/vol-lsu-eng.html
http://www.math.umn.edu/~nykamp/mult ivar/Fall2003/lecture26.pdf
http://www.math.vt.edu/people/javancel/Section.10.1.pdf
http://www.math.wm.edu/~hugo/compl3.html
http://www.mathematics.jhu.edu/matlab/8-4.html
http://www.mathreference.com/ca-mv,local.html
http://www.mathreference.com/la-qf,intro.html
http://www.maths.abdn.ac.uk/~igc/tch/ma2001/notes/node70.html
http://www.maths.abdn.ac.uk/~ igc/tch/mx3503/notes/node79.html
http://www.maths.lse.ac.uk/Courses/MA207/fqmso.pdf
http://www.mpri.lsu.edu/textbook/Chapter2.htm
http://www.numericalmathematics.com/maxima.and_minimal.htm
http://www.psi.toronto.edu/matrix/special.html
http://www.quantlet.com/mdstat/scripts/mva/htmlbook/
mvahtmlnode16.html
http://www.reference.com/browse/wiki/Maxima_and_minima
http://www.reference.com/browse/wiki/Quadratic_form
http://www.riskglossary.com/link/positive_definite.matrix.htm
http://www.sciencenews.org/articles/2006031l/bob9.asp
http://www.Stanford.edu/class/ee263/symm.pdf
http://www.ucl.ac.uk/Mathematics/geomath/level2/pdiff/pd7.html
http://www.ucl.ac.uk/Mathematics/geomath/level2/pdiff/pd8.html
http://www.vision.caltech.edu/mweber/research/CNS248/node22.html