Q. Let PA and PB are two tangents drawn from point p on the line x+2y=3 to the circle x - 1 2 + y - 1 2 = 1 , then find the locus of the circum centre of triangle PAB. Share with your friends Share 0 Varun Rawat answered this Let Pa,b be the point.Since, P Lies on the line x+2y = 3, then it must satisfy it.Now, a + 2b = 3 ⇒b = 3-a2Now, coordinates of P are a, 3-a2Now, circle passes through P, A, B and also passes through the centre of x - 12 + y - 12 = 1.The coordinates of centre of circle x - 12 + y - 12 = 1 are : O1,1Now, centre of circumcircle is mid point of OP.i.e. a+12, 3-a2+12 = a+12, 5-a4Let x = a+12 and y = 5-a4⇒a = 2x - 1 and a = 5 - 4ySo, 2x - 1 = 5 - 4y⇒2x + 4y = 6⇒x + 2y = 3This is the required equation of locus. 1 View Full Answer