BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Cordinate Geometry

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 869
Joined: Wed Aug 26, 2009 3:49 pm
Location: California
Thanked: 13 times
Followed by:3 members

Cordinate Geometry

by heshamelaziry » Thu Aug 27, 2009 5:46 pm
In the xy plane, each point on the circle K has non-negative coordinates and center of K is point (4,7), what is the maximum area for K ???

Answer: 16 * 3.14

Please explain
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 40
Joined: Sat Feb 14, 2009 9:22 am
GMAT Score:460

by GambitOS » Thu Aug 27, 2009 10:42 pm
In x/y coordinate system the radius of the circle K will be x(4) - the closets point to the negative part. So we know the radius and we know that

Area of the circle = pi*r^2
Area=pi(3,14)*4^2=3,14*16

Could I ask you what is the sourse of the question?
Top
Legendary Member
Posts: 869
Joined: Wed Aug 26, 2009 3:49 pm
Location: California
Thanked: 13 times
Followed by:3 members

by heshamelaziry » Thu Aug 27, 2009 11:03 pm
GambitOS wrote:In x/y coordinate system the radius of the circle K will be x(4) - the closets point to the negative part. So we know the radius and we know that

Area of the circle = pi*r^2
Area=pi(3,14)*4^2=3,14*16

Could I ask you what is the sourse of the question?


What do you mean by "the closes point to the negative part" ? The problem here is whether the circle is touching x-axis, y-axis or just in quadrant one and not touching either.

This problem from www.mba.com free tests.

Thanks,
Top
Master | Next Rank: 500 Posts
Posts: 231
Joined: Thu Apr 12, 2007 2:45 am
Thanked: 5 times
Followed by:1 members

Re: Cordinate Geometry

by winnerhere » Fri Aug 28, 2009 12:34 am
heshamelaziry wrote:In the xy plane, each point on the circle K has non-negative coordinates and center of K is point (4,7), what is the maximum area for K ???

Answer: 16 * 3.14

Please explain
If u draw a circle with radius 4,it will touch the y axis...just picturise it.

U cant go beyond x axis as all co ordinates are positive.

so maximum radius is 4 and maximum area is 16 * 3.14
Top
Post new topic Post Reply
• Page 1 of 1