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Find the equation of circle with PQ as diameter if the line y = x/2 intersects ellipse + at the points P and Q?
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The endpoints of the diameter are intersections of the line y = x/2 with the ellipse + = 1.
To find these endpoints, substitute the line equation to the ellipse equation.
You will get intersection points (x,y) = (,) and (x,y) = (,).
Thus the circle is centered at the origin of the coordinate system and has the radius of = .
The standard equation of the circle is + = 2.5. ANSWER
Solved.