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real tough

by willbeatthegmat » Sun Nov 09, 2008 2:37 pm
What is the least possible distance between a point on the circle x^2 + y^2 = 1 and a point on the line y = 3/4*x - 3?

A) 1.4
B) sqrt (2)
C) 1.7
D) sqrt (3)
E) 2.0

can sum1 elaborate d solution in details
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Re: real tough

by logitech » Sun Nov 09, 2008 3:16 pm
willbeatthegmat wrote:What is the least possible distance between a point on the circle x^2 + y^2 = 1 and a point on the line y = 3/4*x - 3?

A) 1.4
B) sqrt (2)
C) 1.7
D) sqrt (3)
E) 2.0

can sum1 elaborate d solution in details
Well, I really don't think that this question represents the scope of math questions in GMAT.

y = 3/4*x - 3?

x=0, y=-3
y=0, x=4

so it forms a 3-4-5 triangle on the XY plane

if you plot a 90 degrees line from the hypotenuse of the triangle to (0,0)

you will find the Distance + 1

you will also see similir triangles

So;


(D+1)/3 = 4/5

D = 1.4

And please post the OA and I am really having hard time to understand your IM English shud, sum1 and bla bla...
LGTCH
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by willbeatthegmat » Tue Nov 11, 2008 7:40 am
OA is a)1.4...thanks logitech..try gettin familiar wid this IM english
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by tnis0612 » Wed Nov 12, 2008 5:55 am
eym wid u logitech
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by lachlanc » Wed Nov 12, 2008 6:17 am
Another way to solve it is use the area of the triangle

3*4/2 = 6

Now, you realize (as Logitech pointed out) that the hypotenuse of the triangle is 5. Use this as the base of the same triangle to find the distance from the origin (ie the height)

6*2/5 = 2.4

Now subtract 1 to find the distance = 1.4

I also second Logitech's objection to your IM English.
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Re: real tough

by jimmiejaz » Thu Nov 13, 2008 4:14 am
logitech wrote:
willbeatthegmat wrote:What is the least possible distance between a point on the circle x^2 + y^2 = 1 and a point on the line y = 3/4*x - 3?

A) 1.4
B) sqrt (2)
C) 1.7
D) sqrt (3)
E) 2.0

can sum1 elaborate d solution in details
Well, I really don't think that this question represents the scope of math questions in GMAT.

y = 3/4*x - 3?

x=0, y=-3
y=0, x=4

so it forms a 3-4-5 triangle on the XY plane

if you plot a 90 degrees line from the hypotenuse of the triangle to (0,0)

you will find the Distance + 1

you will also see similir triangles

So;


(D+1)/3 = 4/5

D = 1.4

And please post the OA and I am really having hard time to understand your IM English shud, sum1 and bla bla...
logitech,

can u pls explain the last part abt the similar triangles by drwaing the figure.
i am not able to understand D+1 thing.

Rajiv
What if i have not yet beat the beast, I know i will beat it!!!!!!!!
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Re: real tough

by logitech » Thu Nov 13, 2008 9:40 am
jimmiejaz wrote:

logitech,

can u pls explain the last part abt the similar triangles by drwaing the figure.
i am not able to understand D+1 thing.

Rajiv
Attachments
d1.jpg
LGTCH
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