A variable line passes through M (1, 2) and meets the co-ordinate axes at A and B, then locus of mid point of AB, is equal to

Statement-1: variable line drawn through a fixed point cuts the coordinate axes at A and B.The locus of mid-point of AB is a circle. because Statement 2: Through 3 non-collinear points in a plane,only one circle can be drawn.

A variable plane passes through a fixed point (a,b,c) and meets the co-ordinate axes in A, B, C. Show that the locus of the point common to the planes through A, B, C parallel to the co-ordiante planes is (a)/(x) + (b)/(y)+ (c)/(z) = 1 .

A straight line with negative slope passing through the point (1,4) meets the coordinate axes at A and B.The minimum value of OA+OB is equal to

A straight line through the point (1,1) meets the X-axis at A and Y-axis at B. The locus of the mid-point of AB is