2,853 reputation
21549
bio website anhhuy.ch
location Switzerland
age 22
visits member for 4 years, 2 months
seen 2 hours ago

My name is Anh Huy Truong and I am currently studying mathematics at the ETH Zürich.


1d
revised Prove that $\mathbb{Z}$ is a closed subset of $\mathbb{R}$
edited body
1d
reviewed Approve Prove that $\mathbb{Z}$ is a closed subset of $\mathbb{R}$
Jan
26
reviewed Approve Trigonometry book which develops geometric intuition.
Jan
26
reviewed Looks OK lower bound on matrix norm inequality of sum
Jan
26
reviewed Looks OK Trace of a matrix $A$ with $A^2=I$
Jan
26
reviewed Approve Is it unlikely to get the same number of heads/tails?
Jan
26
reviewed Approve Cohen-Macaulay and regular rings
Jan
20
answered what is the name of this operation: $x^T\otimes B$
Jan
9
comment How to say if Eigenvectors of A are orthogonal or not? without computing eigenvectors
@Andy: en.wikipedia.org/wiki/Symmetric_matrix#Real_symmetric_matrices
Jan
9
comment How to say if Eigenvectors of A are orthogonal or not? without computing eigenvectors
Do you know the Spectral theorem?
Jan
7
revised Predicates and Quantifiers in discrete math
edited tags
Jan
7
comment Predicates and Quantifiers in discrete math
What have you tried so far?
Jan
7
reviewed Approve Operations on sets with answers
Jan
7
reviewed Approve Is time a continuous random variable?
Jan
5
comment Generic method to find a matrix whose null space is given
@Dor: I'm not sure I understand your question. We know we can write $A$ in such a form (with only non-zero elements in one row). By multiplying $A$ with the two vectors $v_1, v_2$ and setting it equal to zero I constrain $A$ such that $\ker(A) = \operatorname{span}(v_1,v_2)$. Does that answer your question? If not, could you try to rephrase it?
Jan
4
answered Generic method to find a matrix whose null space is given
Jan
4
reviewed Approve Regarding functions composition in descrete math
Jan
4
comment Eigenvalue of the substraction of 2 matrices
If you have to prove or disprove the statement "If $A$ and $B$ have the same eigenvalues, then $A-B$ has eigenvalue $0$", then one counterexample is sufficient to disprove the statement. If you want to prove that the statement is true, you'll need to show it for general matrices $A$ and $B$ and not just using one example.
Jan
4
reviewed Approve Why is this $0 = 1$ proof wrong?
Jan
4
reviewed Edit Maximizing volume in Calculus