Home » Ask & Discuss » Mathematics. » Analytical Geometry « Back to Discussion

Analytical Geometry

New kid on the Block

Joined:	25 Jan 2009
Post:	13

3 Feb 2009 19:05:35 IST

0 People liked this

325

the image of pt.(-2,1)by a line mirror be (2,-1) den waz the equation of line mirror

None

the image of pt.(-2,1)by a line mirror be (2,-1) den waz the equation of line mirror

Share this article on:

Comments (8)

abhishek

Cool goIITian

Joined: 10 May 2008

Posts: 83

3 Feb 2009 19:07:56 IST

Like 0 people liked this

Is it x=y.do reply plz

A$PIRing HiGh - dEv aDitYa

Blazing goIITian

Joined: 13 Mar 2008

Posts: 540

3 Feb 2009 19:14:35 IST

Like 0 people liked this

y=x

AViK

Blazing goIITian

Joined: 5 Sep 2008

Posts: 953

3 Feb 2009 19:33:15 IST

Like 1 people liked this

Let A(-2,1) ...& B(2.-1)...

Note tht the mirror wud b perpendicular 2 the line AB....

& will pass thro' the origin as AO =OB (O is origin)....

Slope of AB = (-1-1)/ (2+2) = -1/2

SO....slope of mirror = +2 (coz m1*m2 =-1)

Equation of line mirror => y = 2x

PLz rate...

Vikram Saxena

Forum Expert

Joined: 1 Apr 2007

Posts: 3732

4 Feb 2009 19:52:05 IST

Like 1 people liked this

the image of pt.(-2,1)by a line mirror be (2,-1)

the slope of line mirror is :

m = 2

the mid point lies on the mirror than we have :

mid point = (0,0)

equation of mirror is :

y = 2x

debmalya choudhuri

Blazing goIITian

Joined: 2 Jun 2007

Posts: 465

4 Feb 2009 22:24:01 IST

Like 0 people liked this

for simplyfng problems u may use this directly as a result tat if (a,b) is ne point then its refelction abt y=x is (-a,-b) and abt y=-x is (-b,-a) cheers

prateek punj

Blazing goIITian

Joined: 30 Jan 2008

Posts: 340

5 Feb 2009 13:27:47 IST

Like 1 people liked this

y=2x....for sure....

Aatish Pandit

Blazing goIITian

Joined: 3 Feb 2007

Posts: 1200

7 Feb 2009 15:52:15 IST

Like 0 people liked this

well so many answers...hmmm....let me tell u direct formula to find image of any point about any line.....

let the point is (a,b).......and the line be.....px + qy + r = 0......

then for image (x,y).....

that root at the end is a missprint.....

debmalya choudhuri

Blazing goIITian

Joined: 2 Jun 2007

Posts: 465

7 Feb 2009 22:13:43 IST

Like 0 people liked this

dude actually i feel u wil go mad cramming up so manycformulas tats why just approach through the basics the result obatined is faster it is y=2x.

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team