The locus of the centre of a circle which touches externally the circle `x^(2)+y^(2)=a^(2) and x^(2)+y^(2)=4ax` externally has the equation.

Locus of centres of the circles which touch the two circles x^(2)+y^(2)=16 and x^(2)+y^(2)=16x externally is

Locus of the centre of the circle which touches the x-axis and also the circle (x-2)^(2)+(y-2)^(2)=4 externally is

The locus of the centre of a circle which touches externally the circle x^(2)+y^(2)-6x-6y+14=0 and also touches the y-axis is given by the equation.

The locus of the centre of a circle which touches externally the circle x^(2)+y^(2)-6 x-6 y+14=0 and also touches the y -axis is given by the equation

The locus of the centres of the circles which touch x^(2)+y^(2)=a^(2) and 'x^(^^)2+y^(^^)2=4ax externally

The locus of centre of circle which touches the circle x^(2)+y^(2)=1 and y- axis in 1 st quadrant is