Mathematics Higher Level Robert Joinson

©Sumbooks2002Higher Level85 Equation of a Circle1) Two points ( 75,5) and ( 6,– 8)lie on a circle x 2 + y 2 = r 2 where r is theradius of the circle with its centre at theorigin (0,0), What is the radius of the circle?y.( 75,5)x.( 6,– 8)2) The diagram shows the graph of the circlex 2 + y 2 = r 2 and three parallel straightlines.a) Which line has the equationyABy = x + 6 ?b) What is the value of r?Cc) What are the equations of the other twographs?xd) At which points does graph B intersectwith the circle?3) At which points does the line y = 2x – 4 intersect with the circle x 2 + y 2 = 100?4) a) At which points does the line y = – 7 cut the circle x 2 + y 2 = 100 ?b) Write down the co-ordinates of the points at which the line y = 7 cuts this circle.15) One of the points at which the line y = --x – 2 intersects with the circle x 2 + y 2 = r 2 is2(–5,–4.5)a) What is the value of r? Leave your answer as a surd.b) What are the co-ordinates of the other point of intersection?