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Jim Haddocc
  • Member for 7 years, 11 months
  • Last seen more than a month ago
  • India
79 votes
Accepted

How was the area formula for a circle ($A = \pi r^2$) derived before the introduction of calculus?

10 votes

Proving that a matrix is invertible without using determinants

8 votes
Accepted

Prove that midpoints of chords passing through a certain point lie on a circle

5 votes

Number of elements $n \in \{1, ..., 100 \}$ such that $n^{4} - 20n^{2} + 100$ is of the form $k^{4}$ with $k$ an integer.

5 votes
Accepted

Simplification of Gamma

4 votes

Is the transformation possible?

4 votes

How to prove that the Binet formula gives the terms of the Fibonacci Sequence?

4 votes

Can $7n + 13$ ever equal a square?

4 votes
Accepted

Need to prove: $\sum_{n=1}^{\infty}{a_n}$ converges $\implies\sum_{n=1}^{\infty }\frac{\sqrt{a_n}}{n}$ converges

3 votes

How to find the limit $lim_{t \to0+}\frac{e^{-1/t}}{\sqrt t}$

3 votes
Accepted

Find all possible values of c

3 votes
Accepted

The limit as x approaches to infinity where c is a constant

3 votes

How to solve $\frac{1}{1000.1998}+\frac{1}{1001.1997}+\cdots+\frac{1}{1998.1000}$

3 votes

Determining which points cannot lie on a circle

3 votes

how to calculate 10% above and 10 % below a number?

3 votes

Number of Integer solution

3 votes
Accepted

Prove that $4| \sigma(4k+3)$ for each positive integer $k$

2 votes

Binomial sum involving power of $2$

2 votes

If we have $Ax=Bx,\forall x$ , can we derive that $A=B$?

2 votes
Accepted

Finding the values of a and b in the function $f(x) = x^2 + ax + b$

2 votes
Accepted

Formally prove that any number is between two multiples of $n$?

2 votes
Accepted

For $a\in R$ . calculate $\lim\limits_{n\to\infty}\frac{1}{n}$( $( a+\frac{1}{n})^2 + (a +\frac{2}{n})^2+.....+( a + \frac{n-1}{n})^2$)

2 votes

Prove or disprove that $n^2-1$ is composite whenever $n$ is a positve integer greater than 2.

2 votes
Accepted

The function $f$ defined on $[0,1]$ to be $t \rightarrow \sum \limits_{i=1}^{n}|tx_i+(1-t)y_i|^p$ attains its maximum value at either $0$ or $1$

2 votes
Accepted

Maclaurin Series for Implicit Differentiation

2 votes
Accepted

Lagrangian of bead on a wire

2 votes

How to prove that $e=3-\frac{1}{2!1\cdot 2}-\cdots-\frac{1}{n!(n-1)n}-\cdots$?

2 votes
Accepted

similar function toward a recurrence function

2 votes

How do we know phasors solve differential equations?

2 votes
Accepted

The power series of $f(x)= \frac{1}{a-x}$