Analyzing the Setup
The equation (x−1)2+y2=1 describes a circle with its center at (1,0) and a radius of 1.
By observing the equation, we see that the origin (0,0) lies exactly on the boundary of this circle. This serves as the fixed starting point for all chords considered in this problem.
The Master Equation
Expanding the circle equation (x−1)2+y2=1 yields:
This simplifies to the standard form:
Let P(h,k) be the midpoint of a chord originating from (0,0). We utilize the chord equation formula T=S1, where T represents the tangent-like expression at (h,k) and S1 is the value of the circle equation at (h,k).
Constructing the Locus
For the circle x2+y2−2x=0, we apply the standard replacement rules: x2→xh, y2→yk, and x→2x+h.
This gives us the expression for T:
Next, we calculate S1 by substituting the midpoint (h,k) into the circle equation:
Setting T=S1, we obtain the equation of the chord:
Applying the Origin Constraint
Since every chord passes through the origin (0,0), the coordinates (0,0) must satisfy the chord equation. Substituting x=0 and y=0 into the equation above:
This simplifies to:
Rearranging the terms, we arrive at the final relation:
Final Result
Replacing (h,k) with the general coordinates (x,y), we find the locus of the midpoints:
This result represents a circle with its center at (21,0) and a radius of 21. The midpoints of all chords drawn from the origin to the original circle trace out this smaller, perfectly defined geometric path.