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David's user avatar
David's user avatar
David
  • Member for 8 years, 4 months
  • Last seen more than 8 years ago
50 votes

Prove the following trigonometric identity without a calculator involved

21 votes

What are the Laws of Rational Exponents?

16 votes
Accepted

Three angles are linearly independent over $\mathbb{Q}$?

15 votes
Accepted

Circle enclosing all but one of $n$ points

14 votes

Examples of a categories without products

13 votes

Are there any objects which aren't sets?

11 votes

Irreducible of $\mathbb Z/p\mathbb Z$.

10 votes
Accepted

The minimum value of $ f(x) = | x - 1 | + | x - 2 | + | x - 3 | $ is?

10 votes
Accepted

The smallest symmetric group $S_m$ into which a given dihedral group $D_{2n}$ embeds

8 votes
Accepted

Find power series using long division

8 votes

Is triangle congruence SAS an axiom?

8 votes
Accepted

Is $k+p$ prime infinitely many times?

7 votes

Which of the following is not a prime number?

7 votes
Accepted

Given three arbitrary points in the euclidean plane, is there a way to homeomorphic map the plane so that the points become colinear?

7 votes

algebraic conjugate

6 votes
Accepted

Let $f: \Bbb R \to [0,\infty)$ be a continuous function such that $g(x)=(f(x))^2$ is uniformly continuous. Which of the following is always true?

6 votes

Proving a group of order $77$ has a subgroup of order $7$ without Sylow theorem.

6 votes

Some equations from Russian maths book.

6 votes
Accepted

Should I continue trying to solve Spivak or pick up a lighter book?

6 votes
Accepted

Definition of Inverse in Linear and Abstract Algebra

6 votes

Examples of fields with characteristic $2$.

6 votes
Accepted

Cauchy like inequality $(5\alpha x+\alpha y+\beta x + 3\beta y)^2 \leq (5\alpha^2 + 2\alpha \beta +3\beta ^2)(5x^2+2xy+3y^2)$

6 votes
Accepted

Which of the following can NOT be the possible value of $P(A \cup B)$?

6 votes

In how many of the integer numbers between 0 and 10,000 does the digit 3 appear to the left of 4

5 votes

Construct a triangle with its orthocenter and circumcenter on its incircle.

5 votes
Accepted

Show $p(x)$ is a primitive polynomial

5 votes

How to derive the equation of tangent to an arbitrarily point on a ellipse?

5 votes
Accepted

How many integers between $1$ and $2016$ are divisible by a nontrivial cube $p^3$, $p > 1$?

5 votes

How many pairs are in $(B,C) \in P(A) \times P(A)$ such that $B \subseteq C$

5 votes

Lebesgue measure has the Darboux property

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