Q70.The number of common tangents of the circles given by x2 + y2 −8x −2y + 1 = 0 and x2 + y2 + 6x + 8y = 0 is (1) one (2) four (3) two (4) three
What This Question Tests
The question requires finding the centers and radii of the two given circles and then using the relationship between the distance between their centers and their radii to determine the number of common tangents.
Concepts Tested
Formulas Used
Center (-g, -f) and radius sqrt(g^2+f^2-c) for x^2+y^2+2gx+2fy+c=0
Distance formula between two points
Conditions for number of common tangents based on distance between centers and radii
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📋 Question Details
- Chapter
- Circles
- Topic
- Common tangents of two circles
- Year
- 2012
- Shift
- 26 May Online
- Q Number
- Q70
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 11: Conic Sections (specifically Circles)
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