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Positive Definite Matrices — Gilbert Strang
Mathematics · positive-definite-matrices-tests-for-positive-definiteness
Problem What is the quadratic f = a x 2 + 2 b x y + c y 2 f = ax^2 + 2bxy + cy^2 f = a x 2 + 2 b x y + c y 2 f f f d 1 ( ) 2 + d 2 ( ) 2 d_1(\;)^2 + d_2(\;)^2 d 1 ( ) 2 + d 2 ( ) 2 A = [ 1 2 2 9 ] and A = [ 1 3 3 9 ] . A = \begin{bmatrix} 1 & 2 \\ 2 & 9 \end{bmatrix} \quad \text{and} \quad A = \begin{bmatrix} 1 & 3 \\ 3 & 9 \end{bmatrix}. A = [ 1 2 2 9 ] and A = [ 1 3 3 9 ] . Browse the problem library