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A hyperbola passes through the point `P(sqrt(2),sqrt(3))`and has foci at `(+-2,0)dot`Then the tangent to this hyperbola at `P`also passes through the point : |
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Answer» `x^2/a^2-y^2/b^2=1` `x^2/a^2-y^2/(a^2(e^2-1))=1` `x^2/a^2=y^2/(4-a^2)=1` `(sqrt2)^2/a^2-(sqrt3)^2/(4-a^2)=1` `2/a^2-3/(4-a^2)=1` `(8-2a^2-3a^2)/(a^2(4-a^2))=1` `8-2a^2-3a^2-4a^2+a^4=0` Let`a^2=t` `t^2-9t+8=0` `(t-1)(t-8)=0` `t=1,8` `a^2=1` `|a|=1` `e=2` `b^2=1(4-1)=3` `x^2/1-y^22/3=1` `sqrt2/1x-sqrt3/3y=1` `sqrt2x-y/sqrt3=1` `4-3=1` `1=1` Option 4 is correct. |
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