Step 1: Finding the center and radius of the given circle Rewriting the given equation, \[ x^2 + y^2 - 6x + 6y + 17 = 0 \] Completing the square: \[ (x - 3)^2 - 9 + (y + 3)^2 - 9 + 17 = 0 \] \[ (x - 3)^2 + (y + 3)^2 = 1 \] So, the center is \( (3, -3) \) and radius \( R = 1 \).
Step 2: Finding the required circle The required circle is externally tangent, meaning its center lies along the normal lines. Using the given normal line condition, we solve for the appropriate equation: \[ x^2 + y^2 - 6x - 2y + 1 = 0. \]
If the equation of the circle whose radius is 3 units and which touches internally the circle $$ x^2 + y^2 - 4x - 6y - 12 = 0 $$ at the point $(-1, -1)$ is $$ x^2 + y^2 + px + qy + r = 0, $$ then $p + q - r$ is:
If the curves $$ 2x^2 + ky^2 = 30 \quad \text{and} \quad 3y^2 = 28x $$ cut each other orthogonally, then \( k = \)