Write the condition so that circles `x² + y^2 + 2ax + c = 0` and `x² + y^2 + 2by + c = 0` touch externally.

Write the condition so that circles x^(2)+y^(2)+2ax+c=0 and x^(2)+y^(2)+2by+c=0 touch externally.

If two circles x^(2) + y^(2) - 2ax + c = =0 and x^(2) + y^(2) - 2by + c = 0 touch each other , then c =

If the circles x^(2) +y^(2) = a and x^(2) + y^(2) - 6x - 8y + 9 = 0 touch externally then a =

Show that the circles x^2 +y^2 + 2ax + c = 0 and x^2 + y^2 + 2by + c = 0 touch each other if 1//a^2 + 1//b^2 = 1//c.

If the circles x ^2 + y ^2 + 2ax + c = 0 and x ^2 + y ^2 +2by + c = 0 touch each other, prove that 1/a ^2 + 1 b ^2 = 1/c

The condition that the circles x^(2)+y^(2)+2ax+c=0, x^(2)+y^(2)+2by+c=0 may touch each other is

The condition that the circles x^(2)+y^(2)+2ax+c=0, x^(2)+y^(2)+2by+c=0 may touch each other is

The condition that the circles x^(2)+y^(2)+2ax+c=0, x^(2)+y^(2)+2by+c=0 may touch each other is