1.3 Coordinate geometry in the (x, y) plane

The circle $C\,$ has the equation $x^2 + y^2 - 8x + 6y + 5 = 0$

a.

Find (i) the coordinates of the centre of $C\,$ and (ii) the exact radius of $C$ .

[3]

b.

The line with equation $y = k$ where $k\,$ is a constant, is a tangent to $C$ . Find the possible values of $k$ .

[2]

The circle $C\,$ has the equation $x^2 + y^2 - 8x + 6y + 5 = 0$

a.

Find (i) the coordinates of the centre of $C\,$ and (ii) the exact radius of $C$ .

[3]

b.

The line with equation $y = k$ where $k\,$ is a constant, is a tangent to $C$ . Find the possible values of $k$ .

[2]

1.3 Coordinate geometry in the (x, y) plane Questions