In the xy-plane , line l intersects a circle with center at origin. Is the slope of line l equal to zero?
1) line l passes through second quadrant.
2) line l is perpendicular to the tangent of the circle.
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I think the answer should be B not C
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sanju09
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But I don't think either way, because I can visualize the tangent to this circle may or may not be parallel to y-axis. My answer under the given constraints is E.[email protected] wrote:In the xy-plane , line l intersects a circle with center at origin. Is the slope of line l equal to zero?
1) line l passes through second quadrant.
2) line l is perpendicular to the tangent of the circle.
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sana.noor
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i think it should be E
the line with zero slope means its horizontal where the value of y remains zero. the first statement says that its in II quadrant...its insufficient
statement II says its perpendicular to the tangent of the circle. u can draw tangent anywhere and thus wont be sufficient to prove.
together still i cant find the two statements sufficient. u can pass a line with negative slope that passes from II quadrant perpendicular to tangent drawn in quadrant III
the line with zero slope means its horizontal where the value of y remains zero. the first statement says that its in II quadrant...its insufficient
statement II says its perpendicular to the tangent of the circle. u can draw tangent anywhere and thus wont be sufficient to prove.
together still i cant find the two statements sufficient. u can pass a line with negative slope that passes from II quadrant perpendicular to tangent drawn in quadrant III
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Brent@GMATPrepNow
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Target question: Is the slope of line l equal to zero?[email protected] wrote:In the xy-plane , line l intersects a circle with center at origin. Is the slope of line l equal to zero?
1) line l passes through second quadrant.
2) line l is perpendicular to the tangent of the circle.
IMPORTANT: Since a circle can have an infinite number of tangent lines, the answer here is E.
To prove this, let's jump straight to . . .
Statements 1 and 2 combined
Here are two possible scenarios that meet the two given conditions:
Case a:
Case b:
In once case, the slope of line l equals 0, and in the other case, the slope of line l does not equal 0.
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent
Last edited by Brent@GMATPrepNow on Thu Apr 19, 2018 2:25 pm, edited 1 time in total.
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sanju09
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Hi Brent,Brent@GMATPrepNow wrote:Target question: Is the slope of line l equal to zero?[email protected] wrote:In the xy-plane , line l intersects a circle with center at origin. Is the slope of line l equal to zero?
1) line l passes through second quadrant.
2) line l is perpendicular to the tangent of the circle.
IMPORTANT: Since a circle can have an infinite number of tangent lines, the answer here is E.
To prove this, let's jump straight to . . .
Statements 1 and 2 combined
Here are two possible scenarios that meet the two given conditions:
Case a:
Case b:
In once case, the slope of line l equals 0, and in the other case, the slope of line l does not equal 0.
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer = E
Cheers,
Brent
I wonder where and how do you do these drawings, this really makes great sense while explaining Geometry problems. Would you please PM or tell me the same under this thread only.
Warm Regards
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
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Brent@GMATPrepNow
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I draw them using PPT, and then take screenshots (which I paste and crop in Paint)sanju09 wrote: Hi Brent,
I wonder where and how do you do these drawings, this really makes great sense while explaining Geometry problems. Would you please PM or tell me the same under this thread only.
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
If the diagram is there,it will be easy to understand the question.
[email protected] wrote:In the xy-plane , line l intersects a circle with center at origin. Is the slope of line l equal to zero?
1) line l passes through second quadrant.
2) line l is perpendicular to the tangent of the circle.
