Tagged Questions

Questions on the use of algebraic techniques to prove geometric theorems.

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What are the coordinates for the center of the second circle? (Full question in body)

Full Question:A circle has its center at (6,7) and goes through the point (1,4). A second circle is tangent to the first circle at the point (1,4) and has one-fourth the area. What are the coordinates ...
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What is condition for second degree equation to represent a pair of straight lines?

According to my text the necessary and sufficient condition for a general equation of second degree i.e. $ax^2 + 2hxy + by^2 + 2gx + 2fy + c = 0$ to represent a pair of straight lines is that 1) the ...
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Find the coordinates of E, G and H, and calculate the area of shape OFEH

Currently I am looking at a graph of a circle. The diameter is y=2x+3 Tangent at point E cuts the x-axis at F (12;0) 1. find the coordinates of E 2. find the coordinates of G and H (H being the centre)...
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calculate the value of P is the points A(6;5), B(3;2) and C (2p;p+4) are co-linnear

Also honestly have no clue whatsoever. I have tried jotting down a graph and just finding the differences between A and B and minusing them from B to create C. I know this is completely wrong! Please ...
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In a triangle $ABC$ with $A=(1,3) ,B =(q,0), C =(p,-4)$ [closed]

Let $A=(1,3),B =(q,0), C =(p,-4)$, with $p>0$, the slope of $AB$ is $+45^\circ$ and $AC= \sqrt{50}$. Determine the gradient of $AB$ Calculate the equation of the line $AB$ Calculate the value of ...
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Find the equations of the lines of greatest slope and least slope

Find the equations of the lines of greatest slope and least slope on the plane $3x-4y+5z-5=0$ drawn through the point $(1,2,2)$ given that the plane $4x-5y+6z-6=0$ is horizontal. I do not need the ...
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Find minimum of $a+b$ under the condition $\frac{m^2}{a^2}+\frac{n^2}{b^2}=1$ where $m,n$ are fixed arguments

Assume $m,n \in \mathbb{R}$ is fixed. And $a,b(a>b>0)$ satisfied the equation $$\frac{m^2}{a^2}+\frac{n^2}{b^2}=1$$ Find $\min\{a+b\}$
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Given three coordinates (a,b,c), (d,e,f), and (l,m,n), what is the center of the circle in the 3D plane (h,k,i) that contains these three points.

I have tried the following: $$(a-h)^2+(b-k)^2+(c-i)^2=r^2$$ $$(d-h)^2+(e-k)^2+(f-i)^2=r^2$$ $$(l-h)^2+(m-k)^2+(n-i)^2=r^2$$ Subtracted equation 2 from 1, equation 3 from equation 2, and equation 3 ...
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Proving a vector bisect two other vectors

How can I prove the vector: $$\vec{w}=|\vec{u}|\vec{v} + |\vec{v}| \vec{u}$$ bisects the angle between the vectors $\vec{u}$ and $\vec{v}$ ? I have trying using the scalar product, but it does not ...
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Understanding distance between point and line via infimum

The distance between point and line independently on metric is defined by $$d(X, l) = \inf\{d(X, Y)|Y\in l\}.$$ I have troubles understandning how this infimum works. Can someone please give me an ...
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When does $ax+by+c=0$ represents a family of straight lines passing through a fixed point?

a first degree linear equation $ax+by+c=0$ represents a family of straight lines passing through a fixed point if and only if there is linear relationship between a,b and c? How can we prove this? ...
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Equation of a Plane

I realize this may be VERY low level for this forum. I'm practicing for an exam and I just want to verify an answer because I do not have the solutions for this practice test. The question is: Find ...
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PARABOLA : Problem

Find the equation of line touching both the parabolas $$x^2=-32y.......(1)$$ $$y^2=4x.........(2)$$ i have equated slopes of both the parabolas and applied the condition that all the points on ...
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How are trigonometric ratios function of interior angles in a right angled triangle?

How can one assume that the ratio altitude/hypotenuse is a function of angle. For a general right-angled triangle--->Let: Hypotenuse$=c$ Altitude$=a$ Base$=b$ and angle opposite ...
A circle with center at origin passes through three points $P$, $Q$ and $R$ with the line segment $PQ$ as its diameter along $x$-axis. A line passes through $P$ intersects the chord $QR$ at point $D$. ...