Question
The common tangent of x2 + y2 = 4 and 2x2 + y2 = 2 is-
- x + y + 4 = 0
- x – y + 7 = 0
- 2x + 3y + 8 = 0
- None
Hint:
check whether the ellipse lies inside the circle or vice versa or neither.
The correct answer is: None
none
Equation of circle : x2+y2=4
Equation of ellipse: 2x2+y2=2
Radius of circle = 2
Length of major axis of the ellipse = √2
Hence, there is no common tangent as the ellipse lies inside the circle.
there can be no common tangent if one of the curves lie inside the other since a tangent cannot intersect the curve at more than 1 point.
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