The Circle

Question 1

Tangent

Answer 1

A straight line that touches a circle at just one point

Question 2

A straight line that touches a circle at just one point

Answer 2

Tangent

Question 3

Where do the radius and tangent meet

Answer 3

At right angles

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

Question 8

General equation of a circle

Answer 8

x^2 + y^2 + 2gx + 2fy + c = 0

Centre: (-g, -f)

Radius: /g^2 + f^2 - c

The equation g^2 + f^2 - c > 0 for the circle to exist

The coefficients of x^2 and y^2 must be equal to 1

Question 9

x^2 + y^2 + 2gx + 2fy + c = 0

Centre: (-g, -f)

Radius: /g^2 + f^2 - c

The equation g^2 + f^2 - c > 0 for the circle to exist

The coefficients of x^2 and y^2 must be equal to 1

Answer 9

General equation of the circle

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 17

Rule for chords of circles

Answer 17

The perpendicular bisectors of a chord pass through the centre of a circle

Question 18

Circles, origins, and centres

Answer 18

Not all circles have the origin at the centre

Question 19

Find the equation of the circle

Answer 19

Question 20

Find the equation of the circle

Answer 20

Question 21

Find the equation of the circle

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

Answer 25

Question 26

Answer 26

Question 27

Answer 27

Question 28

Answer 28

Question 29

rules for x^2 + y^2 = r^2

Answer 29

Question 30

Answer 30

Question 31

Possibilities of a line and curve intersecting

Answer 31

Question 32

Method of determine points of intersection of a line and a curve

Answer 32

Question 33

Answer 33

Question 34

Answer 34

Question 35

Answer 35

Question 36

Answer 36