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Grade 12Analytical Geometry

If P (2,8) is an interior of a circle x2 + y2 + 4y – p = 0 which neither touches nor intersects the axes, then set for p is -

(a) p < - 1

(b) P < - 4

(c) p > 96

(d) f

Profile image of Rakesh Singh
12 Years agoGrade 12
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1 Answer

Profile image of Jitender Singh
12 Years ago
Ans:
Equation of circle:
x^{2}+(y+2)^{2} = (\sqrt{p+4})^{2}
p+4> 0
\Rightarrow p> -4...........(1)
P(2, 8) is interior to the circle
2^{2}+8^{2}+4.8-p< 0
\Rightarrow p> 100
If there is no condition on touching or intersexting the x- axis, then
\Rightarrow p> 100
If circle is not touching & intersecting the x-axis, we have
0< \sqrt{p+4}< 2
-4< p< 0
Thanks & Regards
Jitender Singh
IIT Delhi
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