For such questions, we should remember the formulae of limit.

 where  and 

For such questions, we should know different formulas of limit.

Let PQ and RS be tangents at the extremities of the diameter ‘PR’ of a circle of radius ‘r’. If PS and RQ intersect at a point ‘X’ on the circumference of the circle, then 2r equals :

For such questions, we should be know different formulas of limit.

If and are two tangents to a circles then radius of the circle is

The locus of center of a circle which passes through the origin and cuts off a length of 4 units from the lineis:

AB is a chord of the circle If (1, -1) is the mid point of the chord AB then the area of the triangle formed by AB and the coordinate axes is

The equation of a plane that passes through (1,2,3) and is at maximum distance from (-1,1,1) is

If the four faces of a tetrahedron are represented by the equations and then volume of the tetrahedron (in cubic units) is

If are distinct non-zero complex numbers and such that then is always equal to

 Equivalent weights of  and 
respectively are

Let and . Then, the line of intersection of planes one determined by and other determined by is perpendicular to