Textbook Answers – Equation of a Circle

July 27, 2016

Workout

Question 1:

(a)  centre (3, 2)  and radius 10

(b)  centre (1, -3) and radius 4

(c)  centre (-5, 7) and radius 2

(d)  centre (-6, -8) and radius 1

(e)  centre (0, 0) and radius 5

(f)  centre (-4, 0) and radius 3

(g)  centre (-2, 7) and radius √5

(h)  centre (6, 1) and radius √20

Question 2:

(a)   (x − 2)² + (y − 7)² = 36

(b)   (x − 4)² + (y + 2)² = 9

(c)   (x + 1)² + (y − 3)² = 16

(d)  (x + 1)² + (y + 2)² = 81

(e)  x² + (y − 5)² = 25

(f)  x² + y² = 64

(g)  (x − 11)² + y² = 3

(h)  (x + 3)² + (y + 7)² = 8

Question 3:

(a)   (x − 4)² + (y – 3)² = 4

(b)  x² + (y + 1)² = 16

(c)  (x + 2)² + (y + 1)² = 1

(d)  (x + 1)² + (y – 1)² = 9

Question 4:

(a)   yes

(b)   no

(c)   yes

(d)   no

(e)   yes

Question 5:  (-6, 0) and (12, 0)

Question 6:  (-3, 0) and (5, 0)

Question 7:  (-8, 0) and (4, 0)

Question 8:  (2 – √67, 0) and (2 + √67, 0)

Question 9:  it does not intercept the x-axis

Apply

Question 1:  (x − 7)² + (y – 2)² = 100

Question 2(a):   A(5, 4)

Question 2(b):  (x − 5)² + (y – 4)² = 25