User Alberto Saracco

8 votes

A polynomial is completely determined by any part of it

answered Dec 14, 2019 at 13:20

6 votes

Accepted

Different ways to find power series for $\frac{1}{2-x}$

answered Dec 1, 2019 at 20:57

5 votes

Accepted

Probability of getting 3 toys

answered Oct 15, 2019 at 10:12

4 votes

Which is bigger: a googolplex or $10^{100!}$

answered Oct 29, 2019 at 17:12

4 votes

A class has 1000 students. 900 are Computer Science students. 200 are Math students. How many are Computer Science Math Dual major students?

answered Dec 18, 2019 at 20:07

3 votes

Putnam 1985 B-1

answered Oct 31, 2019 at 18:00

3 votes

Accepted

$\frac{1}{\sqrt1}+\frac{1}{\sqrt2}+\dots+\frac{1}{\sqrt{n}}<2\sqrt{n}$?

answered Oct 18, 2019 at 12:23

3 votes

Accepted

How many equivalence classes does $\sim$ gives rise to?

answered Nov 2, 2019 at 9:08

3 votes

Accepted

Is there any entity that possess information of magnitude,direction,starting and ending points?

answered Dec 4, 2019 at 11:58

3 votes

Accepted

Basic Probability.

answered Dec 12, 2019 at 9:00

2 votes

A poker deck has $52$ cards, $13$ ranks ${A,2,...,10,J,Q,K}$ and $4$ suits {diamond, club, heart, spade}.

answered Dec 12, 2019 at 14:30

2 votes

General Solution of $|z-a| + |z-b| = c$

answered Dec 15, 2019 at 21:01

2 votes

Accepted

A simple closed curve is longer than the largest inscribed circle

answered Dec 16, 2019 at 8:23

2 votes

Show that a function has exactly one zero

answered Dec 8, 2019 at 7:31

2 votes

What does the equation of the straight lines $7x^2+4xy+4y^2=0$ become when the axes are the bisectors of the angles between them?

answered Dec 10, 2019 at 13:30

2 votes

What exactly is the definition of a graph?

answered Dec 2, 2019 at 21:08

2 votes

Accepted

Complex logarithm of a product

answered Nov 4, 2019 at 17:44

2 votes

Accepted

Double summation with dependent indices

answered Nov 1, 2019 at 12:28

2 votes

Prove that there is no n, such 289 divides $(n-5)(n-12)+51$.

answered Oct 31, 2019 at 22:04

2 votes

Determine the indefinitely differentiable functions of the form $f(x+y)=f(x)+f(y)+xy$

answered Nov 17, 2019 at 14:50

2 votes

Accepted

Is it right that $\{2x : x \in\mathbb{Z}, |x| < 4\} = \{−6,−4,−2,0,2,4,6\}$?

answered Dec 20, 2019 at 9:27

2 votes

Inequation involving summation

answered Dec 20, 2019 at 15:04

1 vote

How do I prove a claim on a recursive formula?

answered Dec 17, 2019 at 12:17

1 vote

Find the boundary of $A$?

answered Dec 18, 2019 at 21:17

1 vote

Show that $z(t)=\frac{1+it}{1-it}$ describes a circumference on the complex plane.

answered Oct 21, 2019 at 16:27

1 vote

Accepted

Finding the extrema of a $f(x,y,z) = xy+yz$ with $x+y+z =1$ and $x^2+y^2+z^2 = 6$

answered Oct 22, 2019 at 12:32

1 vote

Solving inequality with absolute values and fraction

answered Oct 26, 2019 at 20:37

1 vote

Find the derivative of $\frac{x}{x+\frac{x}{x+\frac{x}{x+\cdots}}}$

answered Nov 17, 2019 at 9:02

1 vote

Accepted

Two men consequently flip a «fair» coin (possible outcomes are Head and Tail).

answered Dec 16, 2019 at 19:24

1 vote

Prove that when $f = g - h$ and $g, h$ are measurable nonnegative functions then $f^{+} \leq g$ and $f^{-} \leq h$

answered Dec 15, 2019 at 10:39

Stack Exchange Network

42 Answers

A polynomial is completely determined by any part of it

Different ways to find power series for $\frac{1}{2-x}$

Probability of getting 3 toys

Which is bigger: a googolplex or $10^{100!}$

A class has 1000 students. 900 are Computer Science students. 200 are Math students. How many are Computer Science Math Dual major students?

Putnam 1985 B-1

$\frac{1}{\sqrt1}+\frac{1}{\sqrt2}+\dots+\frac{1}{\sqrt{n}}<2\sqrt{n}$?

How many equivalence classes does $\sim$ gives rise to?

Is there any entity that possess information of magnitude,direction,starting and ending points?

Basic Probability.

A poker deck has $52$ cards, $13$ ranks ${A,2,...,10,J,Q,K}$ and $4$ suits {diamond, club, heart, spade}.

General Solution of $|z-a| + |z-b| = c$

A simple closed curve is longer than the largest inscribed circle

Show that a function has exactly one zero

What does the equation of the straight lines $7x^2+4xy+4y^2=0$ become when the axes are the bisectors of the angles between them?

What exactly is the definition of a graph?

Complex logarithm of a product

Double summation with dependent indices

Prove that there is no n, such 289 divides $(n-5)(n-12)+51$.

Determine the indefinitely differentiable functions of the form $f(x+y)=f(x)+f(y)+xy$

Is it right that $\{2x : x \in\mathbb{Z}, |x| < 4\} = \{−6,−4,−2,0,2,4,6\}$?

Inequation involving summation

How do I prove a claim on a recursive formula?

Find the boundary of $A$?

Show that $z(t)=\frac{1+it}{1-it}$ describes a circumference on the complex plane.

Finding the extrema of a $f(x,y,z) = xy+yz$ with $x+y+z =1$ and $x^2+y^2+z^2 = 6$

Solving inequality with absolute values and fraction

Find the derivative of $\frac{x}{x+\frac{x}{x+\frac{x}{x+\cdots}}}$

Two men consequently flip a «fair» coin (possible outcomes are Head and Tail).

Prove that when $f = g - h$ and $g, h$ are measurable nonnegative functions then $f^{+} \leq g$ and $f^{-} \leq h$