All mind maps topics

Equation of a circleAQA A-Level Maths: Mind map

Standard form
Finding the equation
Completing the square

Equation of a circle

centre and radius

(x−a)2+(y−b)2=r2(x-a)^2+(y-b)^2=r^2centreradius
Points and circle
Lines and axes
Exam tips

Exam questions on Equation of a circle

  1. A circle has equation (x−3)2+(y+2)2=25(x-3)^2+(y+2)^2=25.
    The line x=3x=3 meets the circle at two points. Find their coordinates.2 marks
  2. A circle has equation x2+y2−6x+10y+18=0x^2+y^2-6x+10y+18=0.
    Show that the circle does not meet the xx-axis.2 marks
  3. A circle has centre C(2,−1)C(2,-1) and passes through the point P(5,3)P(5,3).
    Find the equation of the circle.3 marks
See the full worksheet

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).