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.

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Find unknown coordinates of points

I hope it's enough understandable.
Annmn
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How to find the length of a line segment inside of the unit cube?

$$\frac{x}2=y=\frac{z}{-2}$$ What is the length of the segment inside of the unit cube? I guess I should find the intersections of the line and the $x=1,y=1,z=1$ planes but I think this line doesn't pass through the inside of the unit cube. Am I…
St3114
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Points of intersection of two lines

I have two lines that are concurrents and I want to know the point of intersection between them. To find the point my algorithm performs the following equation and replacing the lambda found in one of the equations: $$|\lambda| = \frac{|(\vec{v}_1…
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Coincidents lines

My algorithm to determine whether two lines are coincident (which have been proven previously they are parallel) verifies the following equation: $$ \dfrac{x - x_o}{a} = \dfrac{y - y_o}{b} = \dfrac{z - z_o}{c} = \lambda $$ $x$, $y$ and $z$ are…
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Intersection point of two lines in 3D

I need an algorithm that returns the point of intersection between two lines. The algorithm is capable of determining the relative position then I'm sure the lines will intersect. My question is: I want to avoid linear systems in my program so I…
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Angle bisector equation and orthocenter given, vertex to be found

In triangle $ABC$, let $A(3,4)$ and the equation of angle bisector of $B$ is $y=x$. If orthocenter of triangle is $(2,2)$ and $B(h,k)$, then find $(h,k)$. I cant solve this question, I am confused, what is the use of equation of angle bisector? Some…
diya
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Question based of orthocenter distance from angular points

In an acute angled triangle ABC,$\angle A=20^\circ $,let D,E,F be the feet of altitudes through A,B,C respectively and H is the orthocenter of $\bigtriangleup ABC $.Find $\frac{AH}{AD}+\frac{BH}{BE}+\frac{CH}{CF}$ Since $AH=2R cosA,AD=2R cos A+2R…
diya
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Equation by Graph

Given a random Graph,is there any known way to find an equation for it ? If I create a random graph is there a way that i can find an equation that totally describes my random graph?
nick
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Angle bisector related question

The internal bisectors of the angles of a triangle ABC meet the sides in D,E,and F.Show that area of the triangle DEF is equal to $\frac{2\Delta\times abc}{(b+c)(c+a)(a+b)}$,here $\Delta $is area of triangle ABC If I choose B as origin,C…
Brahmagupta
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Orthocenter and coordinates of a vertex

In a triangle ABC,the vertex A is (1,1) and orthocenter is (2,4).If the sides AB and BC are members of the family of straight lines $ax+by+c=0$,where $a,b,c$ are in arithmatic progression.Then the coordinates of vertex C are (h,k).Find the value of…
Vinod Kumar Punia
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closest point on a plane to another point in $\mathbb{R}^3$

Given $4$ points in $\mathbb{R}^3$: $A(0,2,4);B(-2,6,-2);C(2,-4,8);D(10,2,0)$, find the line equation $AK$ when $K$ is the projection of $D$ on the plane $ABC$. The first thing I did was find the equation for the plane made up of the points…
nofe
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Given a Line Parametrization, Finding another Equation

So I am given a line $l$ with the parameterization, $x=t, y=2t, z=3t$. Now let some point, $p$ be a plane that contains the line $l$ and the point $(2,2,2)$. So given this, how do I find an equation for $p$ in the form $ax+by+cz=d$? My thoughts: I…
rebecca
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A simplified formula for area of triangle when equations of the sides are given

For i = 1, 2, and 3, let $a_ix + b_iy + c_i = 0$ be three equations of 3 (non-special cased) straight lines. From which, the co-ordinates of the vertices can be found. Using these co-ordinates, via the shoe-lace formula, we can found (A), the area…
Mick
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Graphical details of changing functions

I'm struggeling a bit with the transformations of a function when values are changed (for instance an offset to the right etc). So far I have found the following: http://www.drcruzan.com/Images/TransformationEquation.png Are there more…
Gildraths
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Find the line segments cut off by the plane $ax+by+cz+d=0$ on the coordinate axes, if $abcd\neq 0$

I'm reading Pogorelov's Geometry. Find the line segments cut off by the plane $ax+by+cz+d=0$ on the coordinate axes, if $abcd\neq 0$. Writing the equation as $a(x-x_0)+b(y-y_0)+c(z-z_0)=0$, I think that the line segment is $(x-x_0)$. But when the…
Red Banana
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