Maths Worksheet - Circles (answers)

SAEP Matric Success – Zisukhanyo Maths Worksheet Tuesday 21st April 2009 Circles – ANSWERS 1. Study & Master, Standard Grade, Test 16B, Q11 a) (√50 ; 0) and (-√50 ; 0) b) y = -7 or 1 and x = -1 or 7 2. Classroom Mathematics, Exercise 4.3, Q2 3. Classroom Mathematics, Exercise 4.3, Q3 a) x2 + y2 =9 b) x2 + y2 = 7 2 2 c) x + y = 18 d) x2 + y2 = 13 2 2 e) x + y = 10 f) x2 + y2 = 20 4. Classroom Mathematics, Exercise 4.3, Q8 3 or -3 5. Classroom Mathematics, Exercise 4.5, Q1 a) (x – 2)2 + (y – 10) 2 = 16 b) (x + 1)2 + (y – 1) 2 = 3 c) x2 + y2 = 36 d) x2 – 6x +y2 -10y -18 = 0 2 2 e) (x – a) + (y – b) = 9 f) (x + 2)2 + (y + 4) 2 = r2 6. Classroom Mathematics, Exercise 4.5, Q4 The required circle has centre C(4 ; 4) or C(4 ; -4). The equations are x2 – 8x +y2 - 8y + 7 = 0 or x2 – 8x +y2 + 8y + 7 = 0 7. Study & Master, Higher Grade, Test 18, Q 4 a) Centre (3 ; 1) Radius = 3 b) t = 8 or t = -2