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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Coordinates and locus of centroid

A triangle has two of its sides along the co-ordinate axes and its third side is a tangent to the circle $x^2+y^2=a^2$. If the coordinates of the point of contact of the tangent are $(a \cosØ,a \sinØ)$, show that the coordinates of the centroid are…
twa14
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Condition for when finite cylinder and sphere intersect

I feel like the answer to the following question is well known but I have not been able to find a reference to it with exception to a very similar question here and an article on Wikipedia. Given $h, r, R > 0$ and $(x_0, y_0, z_0) \in \mathbb{R}^3$,…
raf21
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Finding minimum distance from given point to cone

So, the task is to find a minimum distance from a given point $T$ to cone. The cone is represented with points $a,b,c$, where points $a$ and $b$ form a line that represent a symmetry axis, and points $a$ and $c$ form a line that represents slant…
untitled
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Is there a relation in geometry in which the third power of a segment is a function of other segments of a triangle?

All the equations in geometry between segments are related to area or line or are nondimensional relations related to trigonometry.Is there a relation in geometry in which the third power of a segment is a function of other segments of a triangle?
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find vector reflected across another vector

I apologize that this may sound like a very basic question, but I can't find any clear answers in my search. I have a vector $\vec{v}$ that I want to reflect across a vector $\vec{n}$. The dot product between the two vectors will be positive, in…
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segment whose ends are the points of intersection between the Euler line and the triangle

I am looking for an alternative way to calculate the DE line segment. D and E are the points of intersection of the Euler line with the sides of the ABC triangle (sides: a, b and c) method 01 - ratio, area and distance between point and…
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A good description of the set of inner points of a polyhedron.

How can I get a good description of the inner points of a polyhedron? I am trying to calculate the volume of a polyhedron by change of variables, but I can't describe the set of points of the polyhedron properly (given its vertices). I look for a…
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Straight Line Definition

Definition: Let $P(x_0, y_0)$ be a point and let $m$ be a real number. The line through $P$ with slope $m$ is the set of all points $Q(x, y)$ with, $y -y_0 = m(x - x_0)$ Does the set of all points $Q(x, y)$ also includes the point $P(x_0, y_0)$…
Samama Fahim
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Simplex preserving transformation in $\Bbb R^2$

I am looking for a transformation that preserves the vertices of a triangle located at the $\Bbb R^2$ simplex and moves a point at $(x_1,y_1)$ to a point inside the triangle $(u_1,v_1)$. I am hoping for an equation that builds a $2 \times 2$ matrix…
Mikhail
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Symmetrical point with respect to a plane

I have the point $A = (10,0,20)$, and I want the coordinates of its symmetrical point $B$ with respect to the plane $\pi = \begin{cases} x=2+3\alpha+\beta\\y=\alpha\\z=\alpha + 2\beta \end{cases}$, how can I do that? Look at the image: image These…
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What is the dimension of the tangent space

Write down the equations of the tangent space $T_aX$ to a submanifold $X = \{f_1 = \cdots = f_k = 0 \}$ backwards $\in a = \{a_1, \cdots a_n \}$. What is the dimension of $T_aX$. I wrote the equations to be $$\frac{\partial f_1}{\partial x_1} (a)…
Kaish
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Intersection point of diagonals

Does this math mobile work? How to build: two identical ABCD quadrilaterals (paperboard) each divided into two parts (triangles) by the diagonals AC and BD. Two rods of lengths AC and BD that cross perpendicularly at point E. The triangles are…
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Find semi perimeter and Area of triangle in terms of $d_1,d_2,d_3,R$ and $|D|$.

For $i=1,2,3$ ; Let $L_i=\{(x,y):x\cos\theta_i+y\sin\theta_i=1\}$ , $A,B$ and $C$ are intersections of $(L_2,L_3),(L_3,L_1)$ and $(L_1,L_2)$ respectively. And $d_1,d_2$ and $d_3$ are lengths of altitudes of the triangle from $A,B$ and $C$,…
ARROW
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Finding the equation of a hyperbola, knowing the equations of its asymptotes and a point on it

Find the equation of the hyperbola, given that transverse axis parallel to the $x$-axis, equations of asymptotes are $4x + y - 7 = 0$ and $3x - y - 5 = 0$ and the hyperbola passes through point $(4,4)$. How could I solve this problem?
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Find equation of non-concurrent curve

A parabola and straight line (red) $$ y-\frac{x^2}{2}-1=0,\quad y-\frac{x}{2}-2=0;\, \tag 1$$ are combined plotted and found to intersect at $ P(-1,1.5),Q(2,3)\;;$ Two more curves (blue) are manipulated to pass through $(P,Q)$ by setting their RHS…
Narasimham
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