Circles `x^2+y^2+4x+d=0, x^2+y^2+4f y+d=0` touch each other, if

The two circles x^(2)+y^(2)-cx=0 and x^(2)+y^(2)=4 touch each other if:

The two circles x^(2)+y^(2)-cx=0 and x^(2)+y^(2)=4 touch each other if:

If the circles x^2+y^2-9=0 and x^2+y^2+2a x+2y+1=0 touch each other, then alpha is (a) -4/3 (b) 0 (c) 1 (d) 4/3

Examine whether the two circles x^2+y^2-2x-4y=0 and x^2+y^2-8y-4=0 touch each other externally or internally .

Examine whether the two circles x^2+y^2-2x-4y=0 and x^2+y^2-8y-4=0 touch each other externally or internally .

Prove that the curves y^2 = 4x and x^2 + y^2 - 6x + 1 = 0 touch each other at the point (1,2)

If the circles x^2+y^2+2lambdax+2=0 and x^2+y^2+4y+2=0 touch each other, then lambda=

Find the coordinates of the point at which the circles x^2+y^2-4x-2y+4=0 and x^2+y^2-12 x-8y+36=0 touch each other. Also, find equations of common tangents touching the circles the distinct points.

Find the coordinates of the point at which the circles x^2-y^2-4x-2y+4=0 and x^2+y^2-12 x-8y+36=0 touch each other. Also, find equations of common tangents touching the circles the distinct points.