6. Circles Flashcards
What is the equation of the line?
(x - a)2 + (y - b)2 = r2 where (a, b) is the centre
How do you work out if a circle intersects a line?
Solve the equations simultaneously
Simplify into a quadratic equation
What is a tangent to the circle?
A straight line that intersects the circle at one point
It is perpendicular to the radius of the circle at the point of intersection
What is a chord to the circle?
A line segment that joins two points on the circumference of a circle
Perpendicular bisector of a chord will go through the centre of the circle
What is the hypotenuse of a right angled triangle inside a circle?
The diameter
How do you find the centre of a circle when given three points on the circumference?
Find the gradients of two chords
Find the full equations of the perpendicular bisectors of the chords
Find the coordinates of the point of intersection between the two perpendicular bisectors
How do you divide polynomials?
Use: x3 + 2x2 - 17x + 6 by (x - 3)
See card
