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If two perpendicular tangents can be drawn from the origin to thecircle `x^2-6x+y^2-2p y+17=0`, then the value of `|p|`is___ |
Answer» Correct Answer - 5 The equation of the given circle is `x^(2)+y^(2)-6x-2py+17=0` or `(x-3)^(2)+(u-p)^(2)=(p^(2)-8)` (1) Also, `(0,0)` lies outside the circle. The equation of director circle of `S=0` will be `(x-3)^(2)+(u-p)^(2)=2(p^(2)-8)` (2) Tangents drawn from `(0,0)` to circle (1) are perpendicular to each other. Therefore, `(0,0)` must lie on director circle. Hence, `(0-3)^(2)+(0-p)^(2)=2(p^(2)-8)` or `p^(2)=25` or `p= +-5` |
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