1.

If the latus rectum of a hyperbola forms an equilateral triangle with the vertex at the center of the hyperbola ,then find the eccentricity of the hyperbola.

Answer» `(a^2e^2)/(a^2)-y^2/b^2=1`
`e^2-1=y^2/b^2`
`y^2=b^2(e^2-1)`
`y=pmbsqrt(e^2-1)`
`tan30^o=(AD)/(OD)`
`1/sqrt3=(bsqrt(e^2-1))/(ae)`
Squaring both sides
`1/3=(b^2(e^2-1))/(a^2e^2)`
`e^2/(e^2-1)=3(b^2/a^2)`
`e=c/a=sqrt(a^2+b^2)/a^2=sqrt(1+b^2/a^2`
`e^2=1+b^2/a^2`
`b^2/a^2=e^2-1`
`e^2=3(e^2-1)`
`e^2/3=(e^2-1)^2`
`pme/sqrt3=e^2-1`
`sqrt3e^2-e-sqrt3=0`
`e=(1pmsqrt(1+12))/(2sqrt3)`
`e=(1+sqrt13)/(2sqrt3)`
`e=(-1+sqrt13)/(2sqrt3)`


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