Skip to main content
Kotaka Danski's user avatar
Kotaka Danski's user avatar
Kotaka Danski's user avatar
Kotaka Danski
  • Member for 6 years, 6 months
  • Last seen this week
4 votes
5 answers
97 views

Given $x^2+x-a<3$, solve for $a$ so that there is at least one solution $<0$

4 votes
3 answers
112 views

$Y\sim Poi(\lambda)$ trials are conducted with a probability of success $p$. Find the distribution of the number of successful trials.

3 votes
2 answers
268 views

There are two multisets of circles and squares. Probabilty of pulling a circle from second multiset after two transfers between the two sets

3 votes
1 answer
99 views

Find the radius of convergence of $\sum_{n=0}^{\infty}{\ln\left(\cos{\frac{1}{3^n}}\right)x^n}$

2 votes
0 answers
248 views

What does the symbol ⇴ mean?

2 votes
3 answers
71 views

$\sqrt{x}+\sqrt{2-x}\geq a$ has a solution with interval $\leq 3$. [Solve for "a"]. [closed]

2 votes
2 answers
59 views

Find $\lim\limits_{(x,y)\to(1,-1)}{\frac{e^{x-y}\tan{(x+y)}}{x^2-y^2}}$

2 votes
2 answers
682 views

Main period of $f(x)=\cos 5x+\cos 10x$

2 votes
1 answer
219 views

Four cards are randomly chosen without replacement from an ordinary deck of 52 playing cards.

2 votes
4 answers
80 views

Given that $2x^2-4xy+6y^2=9$, find the biggest and lowest value of $2x-y$

1 vote
2 answers
243 views

Find the min/max values of $f(t)=\cos(t)+t \sin(t)$ for $t \in [0, \pi/2]$

1 vote
2 answers
71 views

Find the Maclaurin series of $\ln{(x+\sqrt{x^2+1})}$ with accuracy up to $o(x^{2n})$

1 vote
2 answers
41 views

Find the extrema of $f(x)=(x^2+2x-7)e^{|x+2|}$

1 vote
6 answers
225 views

Find $\int{x\sqrt{1-x^2}\arcsin{x}dx}$

1 vote
2 answers
56 views

Finding the intervals of increase and decrease and concavity of $y=\frac{\sqrt{1+|x-2|}}{1+|x|}$

1 vote
1 answer
134 views

Find all intervals $\mathbb X$ of real numbers for which the function $f(x)$ is invertible

1 vote
1 answer
54 views

Prove that $f(x)$ has either a biggest or lowest value.

1 vote
1 answer
33 views

Is the integral $\int_0^1{\frac{dx}{\sqrt[3]{x(e^x-e^{-x})}}}$ convergent?

1 vote
0 answers
64 views

Examine for conditional and absolute convergence: $\int_1^\infty \frac{\cos y\,\mathrm{d}y}{(y+\sin y)^\alpha}$

1 vote
1 answer
46 views

How to use similar ($\sim)$ functions correctly (if they change their signs)

0 votes
1 answer
34 views

Prove that $f(x,y)=\frac{x^2-4xy+2y^2}{e^{|x|+|y|}}$ is bounded and find its biggest and lowest values

0 votes
0 answers
86 views

Prove that the function $f(x,y)=|y|\sin(x)$ is differentiable at $(0,0)$

0 votes
1 answer
79 views

Present as Maclaurin series the function $f(x)=\ln\left(\pi\sqrt{\frac{2+x}{2-x}}\right)+\arctan{\frac{1-x}{1+x}}$ and find the radius of convergence

0 votes
1 answer
65 views

Examine for convergence $\sum\limits_{1}^{\infty}{(-1)^k\sin{\frac{1}{\sqrt{k}}}}$

0 votes
1 answer
34 views

Apply polar change of coordinates to $(x^2+y^2)^2y''=(x+yy')^3$

0 votes
1 answer
76 views

If $\sum\limits_{0}^{\infty}{5^n.a_n}$ converges and $\sum\limits_{0}^{\infty}{(-5)^n.a_n}$ diverges, choose the correct answer

0 votes
0 answers
454 views

Transshipment problem with unbalanced demand and supply

0 votes
2 answers
45 views

Solve $x^2(y'+26)=y^2+xy$

0 votes
1 answer
913 views

System of 4 linear equations with 4 variables and two parameters

0 votes
2 answers
79 views

Find $\lim_{x\to \infty}{(\frac{\sqrt{x^2-x}}{x} + \frac{1}{4}\sin{\frac{2}{x})^{x^2+\sin{3x}}}}$