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

Analytical Geometry

Scorching goIITian

Joined:	3 Dec 2007
Post:	260

15 Apr 2008 16:08:02 IST

0 People liked this

370

circles

None

d length of d chord of d circle x^2+y^2+4x-7y+12=0 along d y-axis is ...........

d no.of points with integral co-ordinates dat r integral coordinates dat r interior to d circle x^2+y^2=16

P(rt2,rt2) is a point on d circle x^2+y^2=4 & Q is another point on d circle such dat arc PQ=1/4 (circumcircle) d coordinates of Q r

Share this article on:

Comments (2)

sreeraman nagasubramaniyan

Blazing goIITian

Joined: 17 Jan 2008

Posts: 510

15 Apr 2008 18:13:44 IST

Like 1 people liked this

$\mbox{We require integral solutions of} \ x^2+y^2<16 \\ \\ \mbox{to obtain the integral pts. within the circle} \\ \\ \mbox{Possibilities are} \ (0,1),(0,2),(0,3) \\ \\ \mbox{Now x and y coordinates can interchange} \\ \\ \mbox{Also we could have them as negative} \\ \\ 3*4 = 12 \\ \\ \mbox{Doing the same multiplication for} \ (1,1),(1,2),(1,3),(2,2),(2,3) \\ \\ \mbox{we get} \ 32 \ \mbox{cases} \\ \\ \mbox{Now adding} \ (0,0) \\ \\ \mbox{We get the final answer as} \ 45$

chemicaltester

Scorching goIITian

Joined: 12 Mar 2008

Posts: 233

15 Apr 2008 20:11:23 IST

Like 0 people liked this

to find length of chord on y axis
put x = -0 in equatioon
u will find a quadratic eqntion in y
i.e
y^2 -7y +12 =0
hence y=3 or 4
so distance between two point on chord is 1 unit

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