J. Dunivin's user avatar
J. Dunivin's user avatar
J. Dunivin's user avatar
J. Dunivin
  • Member for 9 years, 3 months
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7 votes

Prove $\gcd(a+b, a-b) = 1$ or $2\,$ if $\,\gcd(a,b) = 1$

5 votes
Accepted

How does (sin2x)(cos2X) = (1/2)(sin4x)?

3 votes

Evaluate the limit of $(f(2+h)-f(2))/h$ as $h$ approaches $0$ for $f(x) = \sin(x)$.

3 votes

Contrapositive of the statement with quantifiers

2 votes
Accepted

Is $f(x)=x^2-4x$ injective and surjective?

2 votes

Prove Supremum and Infimum

2 votes
Accepted

If $| X | \leq K$ and $| Y | \leq K$, then how can I show that $| X-Y | \leq 2K$?

2 votes

Conditional Probability and proper use of Bayes' Theorem

2 votes

Showing a function is well-defined: If we assume $a=b$, doesn't it follow that $f(a)=f(b)$?

1 vote

$\log_26-\log_215+\log_220$ Please do not use a calculator

1 vote

Show that if $x \ge 1$, then $x+\frac{1}{x}\ge 2$

1 vote
Accepted

How will we find $P(E)$ instead of $P(\bar E)$?

1 vote

How can I prove that for any $n \ge 4$, $2^n \ge n^2$

1 vote

Effective Methods of Studying in different areas of Math

1 vote

If we have that $A \leq B$ and that $C > B + \epsilon$, where $\epsilon>0$, does it immediately follow that $\mid A-C \mid > \epsilon$?

1 vote

Show that the gcd of an odd integer and an even integer is odd

1 vote

$(r \wedge \neg s) \rightarrow \neg q$

1 vote

Prove by contradiction that there is an $i \in [n]$ such that $x_i \geq 2$ if $x_1,\ldots,x_n \in \mathbb{N} \cup \{0\}$

1 vote
Accepted

Finding a subset for which the following logical statements hold

1 vote
Accepted

Proof involving logical connectives

1 vote

How to show that supremum belongs to the set?

1 vote

Proof involving absolute value and maximums

1 vote
Accepted

Alternating series test question.

1 vote

Proving a conclusion (Logic)

1 vote
Accepted

Find all values of $k$ for which the given augmented matrix corresponds to a consistent system

1 vote

Prove for any $x \in R$, $2[x] ≤ [2x] ≤ 2[x] + 1$

1 vote

How to find the probability that exactly two of the selected objects are balls given that exactly one of them is yellow

1 vote
Accepted

Primary ideal definition ambiguity

1 vote

Proving Pascal's Rule : ${{n} \choose {r}}={{n-1} \choose {r-1}}+{{n-1} \choose r}$ when $1\leq r\leq n$

0 votes
Accepted

Proof that $\mathrm{Var}\bigg(\frac{1}{n} \sum_{i=1}^nY_i\bigg) = \frac{1}{n}\mathrm{Var}(Y_1)$