1.can u explain to me wat an abelian group is?
2.wat is meant by rank of a matrix?
3.if e1 and e2 are the eccentricities of the hyperbolas xy=C^2 and x^2-y^2=C^2
respectively,then e1^2+e2^2=?
4.the directrix of the hyperbola x^2-4(y-3)^2=16 is..?
5.limit x tending to infinity x^2/e^x is..?
6.the eccentricity of the ellipse 4x^2+y^2-8x-6y=3 is..?
7.what is a monoid?