Questions tagged [analytic-geometry]

Questions on the use of algebraic techniques for proving geometric facts. Analytic Geometry is a branch of algebra that is used to model geometric objects - points, (straight) lines, and circles being the most basic of these. It is concerned with defining and representing geometrical shapes in a numerical way.

Analytic geometry, also called coordinate geometry, mathematical subject in which algebraic symbolism and methods are used to represent and solve problems in geometry.

The importance of analytic geometry is that it establishes a correspondence between geometric curves and algebraic equations. This correspondence makes it possible to reformulate problems in geometry as equivalent problems in algebra, and vice versa; the methods of either subject can then be used to solve problems in the other.

Analytic geometry was introduced by René Descartes in $1637$ and was of fundamental importance in the development of the calculus by Sir Isaac Newton and G. W. Leibniz in the late $17^{th}$ cent. More recently it has served as the basis for the modern development and exploitation of algebraic geometry.

6689 questions
1
vote
2 answers

Calculate the spherical intersection location

Having the values (x1 y1 z1), Based on the figure below, I need to find the (x2 y2 z2) O1 ={0 0 0} r1 = R1 O2 = {0 0 L} r2 = R2
alex
  • 131
  • 4
1
vote
3 answers

But how can I calculate the coordinates of a point $Q$ wich lies on $\frac13$ of line $PD$ with $P(2,3)$ and $D(4,-8)$?

To calculate the middle of a line you can just average the points: $x = \dfrac{x_1 + x_2}{2}$ and $y = \dfrac{y_1 + y_2}{2}$ But how can I calculate the coordinates of a point $Q$ wich lies on $\frac13$ of line $PD$ with $P(2,3)$ and $D(4,-8)$? The…
WinstonCherf
  • 1,022
1
vote
2 answers

Find the equation of the tangent lines to the ellipse having a given angular coefficient

Find the equations of the tangent lines to the ellipse $E : x^2/a^2 + y^2/b^2 − 1 = 0$ having a given angular coefficient $m ∈ R$.
1
vote
1 answer

A point and an ellipse

In particular, I have to find the exact value of the minimum distance from $P(- \frac {15}{4},1)$ to the ellipse $ \frac {x^2}{4} + \frac {y^2}{9} =1$ Therefore, if $ \frac {x^2}{a^2} + \frac {y^2}{b^2} = 1$ is an ellipse, with the parameterization…
Steven
  • 359
1
vote
2 answers

Distance of point $P$ from an ellipse

If $ \frac {x^2}{a^2} + \frac {y^2}{b^2} = r^2$ is an ellipse, with the parameterization $x(θ)≔r(a \cos ⁡θ,b \sin⁡ θ ),$ I have to find the value of $θ$ giving the minimum distance from $P(p,q)$ (not on the ellipse) to the ellipse is given by a…
Steven
  • 359
1
vote
2 answers

Angle between planes with x, y and z variables

Problem: Find the angle between the planes $3x-y+z-5=0$ and $x+2y+2z+2=0$. We have been thought 1 formula for solving angles which is : Angle $= Arctan(\frac{m1-m2}{1+m1m2})$ but that is for parallel lines only and for equation with x and y only.…
Jayce
  • 483
1
vote
0 answers

Symmetry in elliptical coordinate

Consider a function $f(x,y)$ in 2D. If it has symmetry in a circle I can write it as $f(r)$, which $r$ is radius in polar coordinate. How can I write it in elliptical coordinate if it has a elliptical symmetry? Can it be written as $f(v)$ or…
1
vote
1 answer

Determine which of two points the object is moving

I have the following task: I have $2$ points on the map (for each point the latitude and longitude is set) and the object on the map with the given direction (the direction is set as the angle with respect to the north). I need to determine to which…
Nikitc
  • 125
1
vote
0 answers

Why the set $ \{ \frac{1}{n} \} \cup\{ 0\}$ is not locally analytic

In 0 all neighboor have infinite points. intuitively it seems that it can not be locally analytical because infinite equations are needed. but why is not it?.
Bohr
  • 23
1
vote
1 answer

How to find the the canonical equation of the projection of the line?

How to find the the canonical equation of the projection of the line $$\frac{1}{3} \left(x - 4\right) = -\frac{1}{2} \left(y + 1\right) = \frac{z}{4}$$ on the plane $$x-3y-z+8=0.$$
Elvin
  • 220
  • 1
  • 9
1
vote
1 answer

Find the condition that one of the lines $ax^2+2hxy+by^2=0$

Find the condition that one of the lines $ax^2+2hxy+by^2=0$ may coincide with one of the lines $a_1x^2+2h_1xy+b_1y^2=0$. My Attempt: Here, $$ax^2+2hxy+by^2=0$$ $$(\dfrac {y}{x})^{2}+\dfrac {2h}{b}.(\dfrac {y}{x})+\dfrac {a}{b}$$ Let $y=mx$ be a…
pi-π
  • 7,416
1
vote
4 answers

Prove that two distinct points are contained by at most one line?

Definition. A line is the set of points $(x,y)\in\mathbb{R}^2$ that satisfy the equation $$ax+by+c=0,$$ where at least one of $a$ or $b$ is non-zero. How to prove that given two distinct points $(p,q)$ and $(r,s)$, there is at most one line that…
user46234
1
vote
1 answer

How to find the tangent cone of the sphere

A given sphere: $$x^2+y^2+z^2+2x-4y+4z-20=0$$ How to find the tangent cone of it ? the vertex of the cone is $(2,6,10)$ thanks very much.
Laura
  • 4,689
1
vote
1 answer

Finding the minimum of the sum of segments.

Given $A(0,0,2)$ and $B(3,4,1)$ in $Oxyz$. Find the minimum value of $AX+BY$ with $X$ and $Y$ being 2 points lying in $Oxy$, and $XY=1$. P/s: I have figured out a solution, but I don't think it is the best one possible. The answer is down…
1
vote
1 answer

How to show that two planes meet a hyperboloid in circles which lie on a sphere

How to show that the planes $2x+3z=5$ and $2x-3y+7=0$ meet the hyperboloid $-x^2+3y^2+12z^2$=$75$ in circles which lie on the sphere $3$$x^2+3y^2+3z^2+4x+36z-110=0$ please help.
liesel
  • 869