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A common tangent to `9x^2-16y^2 = 144` and `x^2 + y^2 = 9`, is |
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Answer» Correct Answer - `y=pm3sqrt((2)/(7))xpm(15)/(sqrt7)` Given equation of hyperbola is `9x^(2)-16y^(2)=144` `"or "(x^(2))/(16)-(y^(2))/(9)=1` The equation of tangent to the hyperbola having slope m is brgt `y=mxpmsqrt(16m^(2)-9)` If it touches the circle, then the distance of the line from the centre of the circle is the radius of the circle. Hence, `(sqrt(16m^(2)-9))/(sqrt(m^(2)+1))=3` `"or "9m^(2)+9=16m^(2)-9` `"or "7m^(2)=18` `"or "m=pm3sqrt((2)/(7))` So, the equation of tangent is `y=pm3sqrt((2)/(7))xpm(15)/(sqrt7)` |
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