The equation of a circle which passes through the points of intersection of the circles \[ 2x^2 + 2y^2 - 2x + 6y - 3 = 0, \quad x^2 + y^2 + 4x + 2y + 1 = 0 \] and whose centre lies on the common chord of these circles is:
\( 4x^2 + 4y^2 + 6x + 10y - 1 = 0 \)
Step 1: Finding the Equation of the Common Chord
The given circles are: \[ 2x^2 + 2y^2 - 2x + 6y - 3 = 0, \] \[ x^2 + y^2 + 4x + 2y + 1 = 0. \] Subtracting the second equation from the first: \[ (2x^2 + 2y^2 - 2x + 6y - 3) - (x^2 + y^2 + 4x + 2y + 1) = 0. \] \[ x^2 + y^2 - 6x + 4y - 4 = 0. \]
Step 2: Finding the Required Circle
A circle passing through the intersection of these two given circles is of the form: \[ S_1 + \lambda S_2 = 0. \] Substituting and simplifying using the condition that the center lies on the common chord, we derive: \[ 4x^2 + 4y^2 + 6x + 10y - 1 = 0. \]
Step 3: Conclusion
Thus, the final answer is: \[ \boxed{4x^2 + 4y^2 + 6x + 10y - 1 = 0}. \]
In the given figure, the numbers associated with the rectangle, triangle, and ellipse are 1, 2, and 3, respectively. Which one among the given options is the most appropriate combination of \( P \), \( Q \), and \( R \)?

The center of a circle $ C $ is at the center of the ellipse $ E: \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 $, where $ a>b $. Let $ C $ pass through the foci $ F_1 $ and $ F_2 $ of $ E $ such that the circle $ C $ and the ellipse $ E $ intersect at four points. Let $ P $ be one of these four points. If the area of the triangle $ PF_1F_2 $ is 30 and the length of the major axis of $ E $ is 17, then the distance between the foci of $ E $ is:
In a messenger RNA molecule, untranslated regions (UTRs) are present at:
I. 5' end before start codon
II. 3' end after stop codon
III. 3' end before stop codon
IV. 5' end after start codon