Maths C1 - CIRCLES

(x – a)² + (y – b)² = r²

^{centre (a, b), radius r}

1. Substitute from line into circle equation to eliminate y

2. Solve the quadratic in x

3. Substitute back into line equation to find corresponding y

4. If there is only one solution, line is a tangent

If two soltions, line is a chord

If no solutions, line & circle don't intersect