intercept of line

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intercept of line

by gmat009 » Thu Nov 13, 2008 11:24 am
CAn someone plz. explain what information do we need to check if a line intersect a circle or not.

Example :-
Circle C and line K lie in the xy plane. If circle C is centered at the origin and has radius 1 , does line K intersect circle C??

(1) The x intercept of line k is greater than 1
(2) The slope of line K is -1/10

In this question what information do we need?

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Re: intercept of line

by logitech » Thu Nov 13, 2008 11:36 am
gmat009 wrote:CAn someone plz. explain what information do we need to check if a line intersect a circle or not.

Example :-
Circle C and line K lie in the xy plane. If circle C is centered at the origin and has radius 1 , does line K intersect circle C??

(1) The x intercept of line k is greater than 1
(2) The slope of line K is -1/10

In this question what information do we need?
Circle equations are given as:

X^2 + Y^2 = (Radius)^2

and a line is described as:

Y = SLOPE X + CONSTANT

so if they intersect there should be at least one X,Y that satisfied the both equation.

And remember you can have one or two points when you draw a line to a circle.

Can you visualize my explanation ?

Going back to the question

1) INSUF , we know that X>1 but how about the slope ?
2) INSUF, we know the slope but where do line intersect X or Y axis

1+2) SUF, we know both

IMO C
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Re: intercept of line

by gmat009 » Thu Nov 13, 2008 11:51 am
logitech wrote:
gmat009 wrote:CAn someone plz. explain what information do we need to check if a line intersect a circle or not.

Example :-
Circle C and line K lie in the xy plane. If circle C is centered at the origin and has radius 1 , does line K intersect circle C??

(1) The x intercept of line k is greater than 1
(2) The slope of line K is -1/10

In this question what information do we need?
Circle equations are given as:

X^2 + Y^2 = (Radius)^2

and a line is described as:

Y = SLOPE X + CONSTANT

so if they intersect there should be at least one X,Y that satisfied the both equation.

And remember you can have one or two points when you draw a line to a circle.

Can you visualize my explanation ?

Going back to the question

1) INSUF , we know that X>1 but how about the slope ?
2) INSUF, we know the slope but where do line intersect X or Y axis

1+2) SUF, we know both

IMO C
Sorry, answer is not C

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Re: intercept of line

by logitech » Thu Nov 13, 2008 12:18 pm
gmat009 wrote:Sorry, answer is not C
Because it is E
Attachments
E.jpg
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