Comments for Problems in Mathematics

Comment on Conditional Probability When the Sum of Two Geometric Random Variables Are Known by Probability that Alice Tossed a Coin Three Times If Alice and Bob Tossed Totally 7 Times | Problems in Mathematics

Wed, 05 Feb 2020 05:38:57 +0000

[…] Its solution can be found in the post: Conditional Probability When the Sum of Two Geometric Random Variables Are Known […]

Comment on Probability that Alice Tossed a Coin Three Times If Alice and Bob Tossed Totally 7 Times by Conditional Probability When the Sum of Two Geometric Random Variables Are Known | Problems in Mathematics

Wed, 05 Feb 2020 05:33:23 +0000

[…] Probability that Alice Tossed a Coin Three Times If Alice and Bob Tossed Totally 7 Times […]

Comment on Probability that Alice Tossed a Coin Three Times If Alice and Bob Tossed Totally 7 Times by Yu

Yu — Sun, 02 Feb 2020 01:43:01 +0000

Dear Pavel,

Thank you for catching the typo. Yes, you are right. I fixed it. Thanks!

Comment on Probability that Alice Tossed a Coin Three Times If Alice and Bob Tossed Totally 7 Times by Pavel

Pavel — Sat, 01 Feb 2020 10:38:14 +0000

Hello.
I believe that after words “Now, as X and Y follow the geometric distribution with parameter p, we have” formula should read P(X=3) not P(X=2).

Comment on Expectation, Variance, and Standard Deviation of Bernoulli Random Variables by Given the Variance of a Bernoulli Random Variable, Find Its Expectation | Problems in Mathematics

Mon, 27 Jan 2020 08:10:10 +0000

[…] For proofs of the formulas, see that post Expectation, Variance, and Standard Deviation of Bernoulli Random Variables. […]

Comment on Conditions on Coefficients that a Matrix is Nonsingular by Yu

Yu — Tue, 21 Jan 2020 19:50:33 +0000

Dear Pavel,

Thank you for catching the mistake. I modified the text. Thanks!

Comment on Conditions on Coefficients that a Matrix is Nonsingular by Pavel

Pavel — Tue, 21 Jan 2020 11:14:25 +0000

Hello.

I believe that in the proof “Suppose that the matrix A is [non]singular. Then the system of linear equations …
has nontrivial solution …”. must be replaced with “Suppose that the matrix A is singular…”

Comment on Matrix Operations with Transpose by Yu

Yu — Tue, 21 Jan 2020 00:14:48 +0000

Dear Pavel,

Thank you for catching the error. I modified it accordingly. Thanks!

Comment on Find the Inverse Linear Transformation if the Linear Transformation is an Isomorphism by Yu

Yu — Tue, 21 Jan 2020 00:10:25 +0000

Dear Mahendra Reddy,

Thank you for catching the error. I modified the problem and now it should be fine.

Comment on Find All the Eigenvalues of Power of Matrix and Inverse Matrix by Yu

Yu — Mon, 20 Jan 2020 23:57:11 +0000

Dear Wizard,

Thank you for your comment.
“So $\frac{1}{\lambda}$, $\lambda=2, \pm 1$ are eigenvalues of $A^{-1}$” was not clear. I meant “So $\frac{1}{\lambda}$ are eigenvalues of $A^{-1}$ for $\lambda=2, \pm 1$.”