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Two rods of lengths 2a and 2b slide along the coordinate axes such that their ends are always concyclic. Find the locus of the centre of the circle. |
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Answer» P(h, k) is the centre of the circle passing through points A, B, C and D (Fig.) where AB = 2a and DC = 2b. This implies and is implied by PA - PC - radius of the circle (PA)2 = (PC)2 (AM)2 + (PM)2 = (PA)2 = (PC)2 = (PN)2 + (CN)2 where M and N are the midpoints of AB and CD, respectively. From the above, we have a2 + k2 = h2 + b2 k2 - h2 = b2 - a2 Locus of (h,k) is y2 - x2 = b2 - a2 |
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