![Exponential Growth and Decay Word Problem [closed]](https://news.conceivablytech.com/uploads/exponential-growth-and-decay-word-problem-closed_720.jpg)
general
Exponential Growth and Decay Word Problem [closed]
Annual sales for a clothing store are $270,000 and are increasing at a rate of 7% per year. Find out how much money is made in 3 years. Use the formula y=...
Apr 09, 2026
Archive: General
general
What is the proof of permutations of similar objects?
What is the proof of permutations of similar objects? I know the formula, but I cannot figure out how to derive it! permutations of similar objects The nu...
Apr 09, 2026
general
Prove through induction that $3^n > n^3$ for $n \geq 4$
I'm new to induction and have not done induction with inequalities before, so I get stuck at proving after the 3rd step. The question is: Use inducti...
Apr 08, 2026
general
Finding the limit of a step function f(x)
I need to find and prove the possible existence of this limit : The function $f(x)$ is defined as follows: $$f(x) = \left\{ \begin{array}{c} 1, x < -2 ...
Apr 08, 2026
general
Proof that a stopped continuous-time martingale is a martingale.
The proof for a stopped discrete-time martingale is shown as follows. Let $M=(M_n)_{n\ge0}$ be a discrete-time martinglae w.r.t. the filtration $(\mathcal...
Apr 08, 2026
general
What is the symbol for primes?
Although there isn't much difference between $\mathbb{Z},\mathbb{N},\mathbb{I}$, they are well-known, and each one gets its own distinguished symbol....
Apr 08, 2026
general
Curl matrix operation
Consider a vector field $\underline{{f}}:\mathbb{R}^3\rightarrow \mathbb{R}^3$. We know that $\underline{\nabla}\cdot\underline{f} = tr(D\underline{f})$, ...
Apr 08, 2026
![3 point to circle. And get radius [duplicate]](https://news.conceivablytech.com/uploads/3-point-to-circle-and-get-radius-duplicate_720.jpg)
general
3 point to circle. And get radius [duplicate]
Me and my collegues stumbled upon a simple geometric question were non of us could provide a quick and descent answer. After some more puzzeling we still ...
Apr 08, 2026
general
What cubic problems did Tartaglia and Fior pose to each other?
I have been researching the history of finding roots to general polynomials and the story of solving for the roots of cubic polynomials ($ax^3+bx^2+cx+d=0...
Apr 08, 2026
general
For all real $x, y$ that satisfy $x^3+y^3=7$ and $x^2+y^2+x+y+xy=4$
I started with $x+y=a$ and $xy=b$ and I rewrote the equations with a and b. I got $$b=a^2+a-4$$ $$x^3+y^3=2a^3+3a^2-12a^2=7$$ $$f(a)=-2a^3+3a^2-12a^2-7=0$...
Apr 08, 2026
