(a)[7]
Use the coordinates of $A$ and $B$ in surd form to deduce the exact length of chord $AB$.
(b)[5]
A tangent to the circle is a straight line through $(10, 0)$ with gradient $m$. Determine the two possible values of $m$.
Mathematics 9709 · AS & A Level · Coordinate geometry
Coordinate geometry — practice question
The circle $x^2 + y^2 = 20$ cuts the line $y = 2x + 5$ at the points $A$ and $B$.