1.

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 :

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.


Discussion

No Comment Found

Related InterviewSolutions