Mathematics
ToBY's user avatar
ToBY's user avatar
ToBY's user avatar
ToBY
  • Member for 3 years, 10 months
  • Last seen this week
  • Bucheon, 경기도 대한민국
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About

Hi! I'm from South Korea. Mathematics is like one of my parts of my life. I'm keeping focusing on improving the skills and challenging various fields of math. Thanks for inviting me here!

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All Questions Answers
Score Newest
question
12
Prove that $\lim_{t \to \infty} \int_1^t \sin(x)\sin(x^2)\,dx$ converges
Feb 14, 2020
question
11
Showing there's no closed-form: $\sum_{n=0}^\infty(-1)^n\frac{\cos^2({3^nx})}{3^n}$
Mar 2, 2020
question
6
Evaluate $\sum_{n=1}^\infty \frac{1}{n}\frac{\ln{n}}{n-\ln{n}}$ [duplicate]
Mar 1, 2020
question
4
Find the function $f(x)$ if $f(x+y)=f(x-y)+2f(y)+xy$
Jan 27, 2020
question
4
If $f''\ge 0$, prove that $f(x+f'(x)) \ge f(x)$
Feb 8, 2020
question
4
If $f'' \ge 0$, $\int_0^2 f(x)dx \ge 2f(1)$
Feb 9, 2020
question
4
Solving the sequence $a_{n+1}=a_{n}a_{n-1}+\sqrt{(a_n^2-1)(a_{n-1}^2-1)}$: proving that $2+2a_n$ is a perfect square
Feb 10, 2020
question
3
The converse of the Implicit Theorem
Oct 21, 2022
question
3
Find $f:[0, 1]\to \mathbb R$ that maximizes $I(f)-J(f)$, where $I(f)=\int_0^1 {x^2 f(x)dx}$, $J(f)=\int_0^1{x\left(f(x)\right)^2 dx}$
Jan 17, 2021
question
3
Prove that midpoint convex and bounded imply continuous
Jun 4, 2020

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