Find the locus of the centroid of the triangle?
A plane moves so that its distance from the origin is a constant $p$. Write down the equation of the locus of the centroid of the triangle formed by its intersection with the three coordinates plane.
I was thinking about this question many times, but i could not get any hint to find the locus of the centroid of the triangle .
But i know that how to find the centroid of triangle we have to add (x+y+z/3,X+Y+Z/3), i don't know the locus of the centroid of the triangle.
if anbody help me i would be very thankful to him
geometry analytic-geometry locus
add a comment |
A plane moves so that its distance from the origin is a constant $p$. Write down the equation of the locus of the centroid of the triangle formed by its intersection with the three coordinates plane.
I was thinking about this question many times, but i could not get any hint to find the locus of the centroid of the triangle .
But i know that how to find the centroid of triangle we have to add (x+y+z/3,X+Y+Z/3), i don't know the locus of the centroid of the triangle.
if anbody help me i would be very thankful to him
geometry analytic-geometry locus
So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53
add a comment |
A plane moves so that its distance from the origin is a constant $p$. Write down the equation of the locus of the centroid of the triangle formed by its intersection with the three coordinates plane.
I was thinking about this question many times, but i could not get any hint to find the locus of the centroid of the triangle .
But i know that how to find the centroid of triangle we have to add (x+y+z/3,X+Y+Z/3), i don't know the locus of the centroid of the triangle.
if anbody help me i would be very thankful to him
geometry analytic-geometry locus
A plane moves so that its distance from the origin is a constant $p$. Write down the equation of the locus of the centroid of the triangle formed by its intersection with the three coordinates plane.
I was thinking about this question many times, but i could not get any hint to find the locus of the centroid of the triangle .
But i know that how to find the centroid of triangle we have to add (x+y+z/3,X+Y+Z/3), i don't know the locus of the centroid of the triangle.
if anbody help me i would be very thankful to him
geometry analytic-geometry locus
geometry analytic-geometry locus
edited Aug 9 '17 at 6:51
Michael Rozenberg
97.4k1589188
97.4k1589188
asked Aug 9 '17 at 5:45
lomberlomber
775320
775320
So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53
add a comment |
So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53
So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53
So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53
add a comment |
3 Answers
3
active
oldest
votes
The equation of a variable plane in intercept form is $$frac xa+frac yb+ frac zc=1$$
Here, $a,b$ and $c$ are intercept on $x,y$ and $z$ axes.
Given, it's distance from origin is constant $$frac{Big|Big(frac xa+frac yb+ frac zc-1Big)_{x=y=z=0}Big|}{sqrt{frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}}}=p(text{constant})$$
And centroid of triangle $$(x,y,z)=left(frac a3,frac b3,frac c3right)$$
Therefore you get $$frac{1}{p^2}=frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}$$
Also, $a=3x,b=3y$ and $c=3z$
$$implies frac{1}{p^2}=frac {1}{9x^2}+frac {1}{9y^2}+frac {1}{9z^2}$$
Hence the desired locus is :
$$color{blue}{frac {1}{x^2}+frac {1}{y^2}+frac {1}{z^2}=frac{9}{p^2}}$$
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
|
show 1 more comment
Let $ac+by+cz+d=0$ be an equation of the plain.
Thus, $abcneq0$ and $$frac{|d|}{sqrt{a^2+b^2+c^2}}=p,$$
which gives $$|d|=psqrt{a^2+b^2+c^2}.$$
Let $Aleft(frac{-d}{a},0,0right)$, $Bleft(0,-frac{d}{b},0right)$ and $Cleft(0,0,-frac{d}{c}right)$ and for the centroid $M$ we obtain
$$Mleft(frac{-d}{3a},frac{-d}{3b},frac{-d}{3c}right),$$
which gives
$$frac{1}{x^2}+frac{1}{y^2}+frac{1}{z^2}=frac{9(a^2+b^2+c^2)}{d^2}=frac{9}{p^2}$$
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
add a comment |
Let $vec s$ be a vector of length $p$. Then the plane's equation is $langlevec s,vec xrangle=p^2$. Provided that no coordinate of $vec s$ is zero, the intercepts are obviously
$$frac{p^2}{s_k}vec e_kquadtext{for $k=1,2,3$}$$
where $vec e_k$ denote the $k^text{th}$ unit vector.
The result may be easily generalized to arbitrary dimensions.
add a comment |
Your Answer
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
The equation of a variable plane in intercept form is $$frac xa+frac yb+ frac zc=1$$
Here, $a,b$ and $c$ are intercept on $x,y$ and $z$ axes.
Given, it's distance from origin is constant $$frac{Big|Big(frac xa+frac yb+ frac zc-1Big)_{x=y=z=0}Big|}{sqrt{frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}}}=p(text{constant})$$
And centroid of triangle $$(x,y,z)=left(frac a3,frac b3,frac c3right)$$
Therefore you get $$frac{1}{p^2}=frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}$$
Also, $a=3x,b=3y$ and $c=3z$
$$implies frac{1}{p^2}=frac {1}{9x^2}+frac {1}{9y^2}+frac {1}{9z^2}$$
Hence the desired locus is :
$$color{blue}{frac {1}{x^2}+frac {1}{y^2}+frac {1}{z^2}=frac{9}{p^2}}$$
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
|
show 1 more comment
The equation of a variable plane in intercept form is $$frac xa+frac yb+ frac zc=1$$
Here, $a,b$ and $c$ are intercept on $x,y$ and $z$ axes.
Given, it's distance from origin is constant $$frac{Big|Big(frac xa+frac yb+ frac zc-1Big)_{x=y=z=0}Big|}{sqrt{frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}}}=p(text{constant})$$
And centroid of triangle $$(x,y,z)=left(frac a3,frac b3,frac c3right)$$
Therefore you get $$frac{1}{p^2}=frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}$$
Also, $a=3x,b=3y$ and $c=3z$
$$implies frac{1}{p^2}=frac {1}{9x^2}+frac {1}{9y^2}+frac {1}{9z^2}$$
Hence the desired locus is :
$$color{blue}{frac {1}{x^2}+frac {1}{y^2}+frac {1}{z^2}=frac{9}{p^2}}$$
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
|
show 1 more comment
The equation of a variable plane in intercept form is $$frac xa+frac yb+ frac zc=1$$
Here, $a,b$ and $c$ are intercept on $x,y$ and $z$ axes.
Given, it's distance from origin is constant $$frac{Big|Big(frac xa+frac yb+ frac zc-1Big)_{x=y=z=0}Big|}{sqrt{frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}}}=p(text{constant})$$
And centroid of triangle $$(x,y,z)=left(frac a3,frac b3,frac c3right)$$
Therefore you get $$frac{1}{p^2}=frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}$$
Also, $a=3x,b=3y$ and $c=3z$
$$implies frac{1}{p^2}=frac {1}{9x^2}+frac {1}{9y^2}+frac {1}{9z^2}$$
Hence the desired locus is :
$$color{blue}{frac {1}{x^2}+frac {1}{y^2}+frac {1}{z^2}=frac{9}{p^2}}$$
The equation of a variable plane in intercept form is $$frac xa+frac yb+ frac zc=1$$
Here, $a,b$ and $c$ are intercept on $x,y$ and $z$ axes.
Given, it's distance from origin is constant $$frac{Big|Big(frac xa+frac yb+ frac zc-1Big)_{x=y=z=0}Big|}{sqrt{frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}}}=p(text{constant})$$
And centroid of triangle $$(x,y,z)=left(frac a3,frac b3,frac c3right)$$
Therefore you get $$frac{1}{p^2}=frac {1}{a^2}+frac {1}{b^2}+frac {1}{c^2}$$
Also, $a=3x,b=3y$ and $c=3z$
$$implies frac{1}{p^2}=frac {1}{9x^2}+frac {1}{9y^2}+frac {1}{9z^2}$$
Hence the desired locus is :
$$color{blue}{frac {1}{x^2}+frac {1}{y^2}+frac {1}{z^2}=frac{9}{p^2}}$$
edited Aug 9 '17 at 5:58
answered Aug 9 '17 at 5:53
Jaideep KhareJaideep Khare
17.7k32568
17.7k32568
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
|
show 1 more comment
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
thanks a lot@ jaideep khare,, but i don't know where i haveto put this centroid coordinates and make a equation
– lomber
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
What about the plane $z=p$?
– Michael Hoppe
Aug 9 '17 at 5:57
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@MichaelHoppe I don't understand what you want to say.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
@lomberlego Check my edit.
– Jaideep Khare
Aug 9 '17 at 6:00
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
The plane given by $z=p$ doesn't have an $x$- or a $y$-intercept.
– Michael Hoppe
Aug 9 '17 at 6:01
|
show 1 more comment
Let $ac+by+cz+d=0$ be an equation of the plain.
Thus, $abcneq0$ and $$frac{|d|}{sqrt{a^2+b^2+c^2}}=p,$$
which gives $$|d|=psqrt{a^2+b^2+c^2}.$$
Let $Aleft(frac{-d}{a},0,0right)$, $Bleft(0,-frac{d}{b},0right)$ and $Cleft(0,0,-frac{d}{c}right)$ and for the centroid $M$ we obtain
$$Mleft(frac{-d}{3a},frac{-d}{3b},frac{-d}{3c}right),$$
which gives
$$frac{1}{x^2}+frac{1}{y^2}+frac{1}{z^2}=frac{9(a^2+b^2+c^2)}{d^2}=frac{9}{p^2}$$
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
add a comment |
Let $ac+by+cz+d=0$ be an equation of the plain.
Thus, $abcneq0$ and $$frac{|d|}{sqrt{a^2+b^2+c^2}}=p,$$
which gives $$|d|=psqrt{a^2+b^2+c^2}.$$
Let $Aleft(frac{-d}{a},0,0right)$, $Bleft(0,-frac{d}{b},0right)$ and $Cleft(0,0,-frac{d}{c}right)$ and for the centroid $M$ we obtain
$$Mleft(frac{-d}{3a},frac{-d}{3b},frac{-d}{3c}right),$$
which gives
$$frac{1}{x^2}+frac{1}{y^2}+frac{1}{z^2}=frac{9(a^2+b^2+c^2)}{d^2}=frac{9}{p^2}$$
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
add a comment |
Let $ac+by+cz+d=0$ be an equation of the plain.
Thus, $abcneq0$ and $$frac{|d|}{sqrt{a^2+b^2+c^2}}=p,$$
which gives $$|d|=psqrt{a^2+b^2+c^2}.$$
Let $Aleft(frac{-d}{a},0,0right)$, $Bleft(0,-frac{d}{b},0right)$ and $Cleft(0,0,-frac{d}{c}right)$ and for the centroid $M$ we obtain
$$Mleft(frac{-d}{3a},frac{-d}{3b},frac{-d}{3c}right),$$
which gives
$$frac{1}{x^2}+frac{1}{y^2}+frac{1}{z^2}=frac{9(a^2+b^2+c^2)}{d^2}=frac{9}{p^2}$$
Let $ac+by+cz+d=0$ be an equation of the plain.
Thus, $abcneq0$ and $$frac{|d|}{sqrt{a^2+b^2+c^2}}=p,$$
which gives $$|d|=psqrt{a^2+b^2+c^2}.$$
Let $Aleft(frac{-d}{a},0,0right)$, $Bleft(0,-frac{d}{b},0right)$ and $Cleft(0,0,-frac{d}{c}right)$ and for the centroid $M$ we obtain
$$Mleft(frac{-d}{3a},frac{-d}{3b},frac{-d}{3c}right),$$
which gives
$$frac{1}{x^2}+frac{1}{y^2}+frac{1}{z^2}=frac{9(a^2+b^2+c^2)}{d^2}=frac{9}{p^2}$$
edited Aug 9 '17 at 6:12
answered Aug 9 '17 at 6:04
Michael RozenbergMichael Rozenberg
97.4k1589188
97.4k1589188
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
add a comment |
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
thanks a lots @ michael Rozenberg
– lomber
Aug 9 '17 at 13:18
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
@lomber lego You are welcome!
– Michael Rozenberg
Aug 9 '17 at 14:26
add a comment |
Let $vec s$ be a vector of length $p$. Then the plane's equation is $langlevec s,vec xrangle=p^2$. Provided that no coordinate of $vec s$ is zero, the intercepts are obviously
$$frac{p^2}{s_k}vec e_kquadtext{for $k=1,2,3$}$$
where $vec e_k$ denote the $k^text{th}$ unit vector.
The result may be easily generalized to arbitrary dimensions.
add a comment |
Let $vec s$ be a vector of length $p$. Then the plane's equation is $langlevec s,vec xrangle=p^2$. Provided that no coordinate of $vec s$ is zero, the intercepts are obviously
$$frac{p^2}{s_k}vec e_kquadtext{for $k=1,2,3$}$$
where $vec e_k$ denote the $k^text{th}$ unit vector.
The result may be easily generalized to arbitrary dimensions.
add a comment |
Let $vec s$ be a vector of length $p$. Then the plane's equation is $langlevec s,vec xrangle=p^2$. Provided that no coordinate of $vec s$ is zero, the intercepts are obviously
$$frac{p^2}{s_k}vec e_kquadtext{for $k=1,2,3$}$$
where $vec e_k$ denote the $k^text{th}$ unit vector.
The result may be easily generalized to arbitrary dimensions.
Let $vec s$ be a vector of length $p$. Then the plane's equation is $langlevec s,vec xrangle=p^2$. Provided that no coordinate of $vec s$ is zero, the intercepts are obviously
$$frac{p^2}{s_k}vec e_kquadtext{for $k=1,2,3$}$$
where $vec e_k$ denote the $k^text{th}$ unit vector.
The result may be easily generalized to arbitrary dimensions.
answered Aug 9 '17 at 6:19
Michael HoppeMichael Hoppe
10.8k31834
10.8k31834
add a comment |
add a comment |
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So the plane is always tangent to the sphere?
– Michael Hoppe
Aug 9 '17 at 5:53