Which equation describes the circle with centre (1, −2) and radius 3?
Answer and explanation
Correct answer: B. (x − 1)² + (y + 2)² = 9
- Step 1: The general form is (x − h)² + (y − k)² = r². Step 2. With h = 1, k = −2: (x − 1)² + (y + 2)² and r² = 9. Answer: (x − 1)² + (y + 2)² = 9. Why not the others: the others flip a sign or use r instead of r².
Practise more Geometry, Trigonometry, Sequences and Probability.
Free questions with an explanation for every one, and full timed Tawjihi (Palestinian General Secondary Examination), Scientific Stream mock tests.
More Geometry, Trigonometry, Sequences and Probability questions
- A right triangle has legs of 6 cm and 8 cm. What is the hypotenuse?
- What is the value of sin 30°?
- What is the area of a circle of radius 7 cm?
- An arithmetic sequence has first term 3 and common difference 4. What is the 10th term?
- What is the sum of the first 10 terms of 3, 7, 11, ...?
- In a geometric sequence 2, 6, 18, ..., what is the next term?