Let a relation R be defined on set of all real numbers by a R b if and only if 1 + ab > 0. Then, R is
reflexive, transitive but not symmetric
reflexive, symmetric but not transitive
symmetric, transitive but not reflexive
an equivalence relation
If sum of two numbers is 6, the minimum value of the sum of their reciprocals is
C.
The normal to the curve x = , y = at any point is such that
it makes a constant angle with x-axis
it passes through origin
it is at a constant distance from origin
None of the above
Differential equation of those circles which passes through origin and their centres lie on y-axis will be