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
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Directional cosines of a line.

Show that if the lines with the directional cosines $(l, m, 0)$ and $(p, 0, q)$ are perpendicular then either $m = \frac {1}{\sqrt{p^2 + q^2}}$ or $q = \frac {1}{\sqrt {l^2 + m^2}}$.
Faisal
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Intersection of symmetric lines.

So I have to determine if these 2 symmetric lines intersect. I converted them to parametric: $$\begin{align} -6+2t&=10+4s\\ -4+3t&=4-2s\\ -1+2t&=-1-4s \end{align}$$ Now, I know I have to solve so I solved it and when t=4 and s=-2 the equation is…
Julio
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Find the focus, vertex, latus rectum of the parabola

The problem is, Find the focus, equation of directrix, vertex, length of latus rectum of the parabola given by, $$\left(\alpha x+\beta y+\gamma\right)^2=Ax+By+C$$ I am stuck with the problem for quite sometime but still don't know how to begin.…
user170039
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How to plot quadratic forms

I'm studying quadratic forms in algebra at the moment and I've been asked to plot the following curve: $$3x^2+4xy+3y^2-\sqrt{2}x+\sqrt{2}y=1$$ I have used the following transformations: $$x_1=x+\frac{2}{3}y$$ $$y_1=y$$ and then…
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Finding the coordinates of a point

I have the $x$ and $y$ values to $2$ points $A(x_a,y_a)$ and $B(x_b,y_b)$. I need to determine the coordinates of a third point $S(x_s,y_s)$ that is at $r$ distance away from both A and B points and lies on a line that is perpendicular to the line…
luka189
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How to find the curve and axis?

We consider the following one-sheeted hyperboloid: $y^2-4x^2+4z^2=4$ This is also a surface (or solid) of revolution. So it must be generated by rotating a curve about an axis. What curve and axis could be those? How can I find them? Thanks.
Surtan
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How to tell whether a point is to the right or left side of a line

I have a line equation in the form ax+by+c=0 and a point p(x,y).How can I determine on which side of the line the point is located?
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Intersection of a cone and a plane.

I need a proof that the intersection of a cone with a plane parallel to the cone's axis is a hyperbola.
chen h.
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Parametric equation with plane equation given

Let $2x + y + z = 2$ be a plane in space. Find the parametric equation of a line of your choice lying in the plane. I find $n=<2,1,1>$ but I need a point to complete.
daleen
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Paramaterizing a Parabola with $3$ points.

Let $A, B, C$ be vectors in $\mathbb R^2$. I want to show that the set $\{A+tB+t^2C\mid t\in\mathbb R\}$ defines a parabola in $\mathbb R^2$, but I'm having a hard time doing so, since I can't solve for one coordinate in terms of the other.
Nishant
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How to find the equation of conics given foci and directrices

Find the equations of the following conics, each with its centre at the origin. (a) A hyperbola with foci $(\pm4, 0)$ and directrices $x= \pm2$ (b) An ellipse with foci $(0, \pm4)$ and directrices $y= \pm6$. Probably some very very simple solutions…
amjh23
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how to calculate an arc center

how to find the center of an arc given start and end points
None
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What is the new point reflected with a respect to fixed line through origin?

If I have $ P(x,y)$, what would be the reflected point with respect to fixed line through origin O? Does it depend on what line I have, If I have $x$ or $2x$ $3x$, they all pass through origin.
aaa
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Find the three dimensional line that goes through point p and is perpendicular to a plane

I am given the point $P(1,0,6)$ and I need to find a line that goes through $P$ and is also perpendicular to $x+3y+z=5$. Background info: I've gotten the help I needed now but when I started I was unaware about the method to find a vector…
ShaneBird
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lines intersection

I have to find intersection of two lines ($AH$ & $CD$) $A(3.42,-1.84,8.56) $ $B(-3.42,3.84,-8.56) $ $C(0.00,16.25,0.00)$ $AH$ is the perpendicular; $CD$ is the median I tried so: Firstly I found coordinates of the point…
Lu Vue
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