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Prove the matrix is positive

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up vote 0 down vote favorite Consider the matrix $A=begin{bmatrix} 1 & 1/2 & 1/3 &dots &1/n \ 1/2 & 1/3 & 1/4 &dots &1/(n+1) \ vdots & vdots & vdots & vdots & vdots\ 1/n & 1/(n+1) & 1/(n+2) & dots& 1/(2n-1) end{bmatrix}$ Prove that $A$ is positive. My work: $A$ is diagonalisable, symmetric but I can't seem to put these facts togheter to help me. I tried to prove by induction (a naive attempt) that the determinant of its minors is always positive but knowing $det(A^{k,k})>0$ there is no information of $det(A^{k+1,k+1}). linear-algebra matrices share | cite | improve this question ...