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The focal distance of a point of a parabola `y^(2)=8x` is 5. Find the abscissa of that point. |
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Answer» `y^(2)=8x` Comparing with `y^(2)=ax` 4a=8 `rArr" "a=2` Equation of directrix x=-a `rArr" "x=-2` `rArr" "x+2=0` Let `(x_(1),y_(1))` be any point on the parabola and its focal distance is 5. `:.` Distance of point `(x_(1),y_(1))` from directrix = distance of point `(x_(1),y_(1))` from focus `rArr" "x_(1)+2=5` `rArr" "x_(1)=3` `:.` Abscissa of required point = 3. |
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