`x^2-x y+y^2-4x-4y+16=0` represents a. a point b. a circle c. a pair of straight line d. none of these

x^(2)-xy+y^(2)-4x-4y+16=0 represents a.a point b.a circle c.a pair of straight line d. none of these

The equation x^2+y^2+2x-4y+5=0 represents a. a point b. a pair of straight lines c. a circle of non zero radius d. none of these

The equation x^(2)+y^(2)+2x-4y+5=0 represents a.a point b.a pair of straight lines c.a circle of non zero radius d.none of these

The equation x^2y^2-9y^2-6x^2y+54 y=0 represents (a) a pair of straight lines and a circle (b) a pair of straight lines and a parabola (c) a set of four straight lines forming a square (d) none of these

The equation x^2y^2-9y^2-6x^2y+54 y=0 represents (a) a pair of straight lines and a circle (b) a pair of straight lines and a parabola (c) a set of four straight lines forming a square (d) none of these

The equation x^2y^2-9y^2-6x^2y+54 y=0 represents (a) a pair of straight lines and a circle (b) a pair of straight lines and a parabola (c) a set of four straight lines forming a square (d) none of these

The equation x^2y^2-9y^2-6x^2y+54 y=0 represents (a)a pair of straight lines and a circle (b)a pair of straight lines and a parabola (c)a set of four straight lines forming a square (d)none of these

The equation x^(2)y^(2)-9y^(2)-6x^(2)y+54y=0 represents (a)a pair of straight lines and a circle (b)a pair of straight lines and a parabola (c)a set tof four straight lines forming a square (d)none of these

If the chord of contact of tangents from a point P to the parabola y^2=4a x touches the parabola x^2=4b y , then the locus of Pdot is a) a cicle b) a parabola c) a straight line d) none of these

The equation 3x^2+4y^2-18x+16 y+43=k (a)represents an empty set, if k 0 (c)represents a point, if k=0 (d)cannot represent a real pair of straight lines for any value of k