Skip to main content

All Questions

Filter by
Sorted by
Tagged with
1 vote
0 answers
47 views

On a general system of linear equations in a derivative problem

For some days a problem that I encountered in the Calculus textbook of mine has been preying upon my mind. The problem is as follows: Determine the expression for the polynomial $F(x)$ given that it ...
Barbatulka's user avatar
4 votes
3 answers
223 views

Prove that $-\sqrt{c}<ab<0$ if $a^4-2019a=b^4-2019b=c$.

Let $a, b$ be two distinct real numbers and let $c$ be a positive real number such that $a^4-2019a=b^4-2019b=c$. Prove that $-\sqrt{c}<ab<0$. I attempted to solve this question using calculus, ...
Michalis Christofi's user avatar
1 vote
1 answer
102 views

How to solve a difficult system

Problem: solve in $\mathbb R^{3}$ this system $$ \begin{cases}y(1+x+x^2+x^3)=\dfrac{z}{16}\\ y^2x(1+x+2x^2+x^3+x^4)=\dfrac{2z+17}{16}\\ y^3x^3(1+x+x^2+x^3)=\dfrac{z}{16}\\ y^4x^6=1 \end{cases} $$ ...
Ellen Ellen's user avatar
  • 2,369
2 votes
1 answer
62 views

Prove that, there no solution for $\left\{a_1,a_2,...,a_{16} \right\}\in \mathbb{R} $

Prove that, there no solution $$\begin{cases} a_1^2+a_2^2+a_3^2+...+a_{16}^2=2017\\ a_1+a_2+a_3+...+a_{16}=1009\\ \end{cases}$$ for $\left\{a_1,a_2,...,a_{16} \right\}\in \mathbb{R} $ I tried $...
nonuser's user avatar
  • 506
1 vote
4 answers
211 views

Solving a system of five polynomials

I am trying to solve the following system of equations for tuple $\left(a,b,c,d,t\right) \in \mathbb{R}^{4} \times [0,1]$, with parameter $\ell\in\mathbb{R}$. $$ \begin{eqnarray} a\frac{t^{2}}{2} - ...
Abhishek Halder's user avatar
3 votes
2 answers
144 views

Solving $4y^4 - 4x^4 + x + y = 0$ (equation system of partial derivates)

I need help solving the following equation system: $$ \frac{\partial}{\partial x} = 8xy + 4y^2 + \frac{y}{x^2 + y^2} = 0 $$ $$ \frac{\partial}{\partial y} = 8xy + 4x^2 - \frac{x}{x^2 + y^2} = 0 $$ I'...
ranwd33's user avatar
  • 33