circle

circle

1. points of intersection

   • axis
     • y-intercept (x =0)
     • x-intercept (y = 0)
   • points of intersection will satisfy equation
   • simultaneous equation
     • with another circle
     • with another line

2. equation

   • (x-a)^2 - (y-b)^2 = r^2
     • radius = r
     • centre = (a , b)
   • x^2 + y^2 + 2gx + 2fy = 0
     • radius = sqrt (f^2 + g ^2 - c)
     • centre = (-g , -h)

3. finding equations

   • of tangents
   • of normal
   • of 2 points
     • given 2 pts
     • involving centre
     • involving axes
     • involving radius/diamenter