1. Welcome

2. Teacher’s Introduction Md. Shamsuzzaman Lecturer (Mathematics) Joypurhat Girls’ Cadet College Mobile: 01716722384 E-mail: suzonjgcc@gmail.com

3. Class: XI Subject: Higher Mathematics Chapter: Four Time: 40 Minutes Dated: 06/01/2016

4. What type of picture ? Circle

5. 1. To say what is the general equation of circle. 2. Determine the equation of the circle with given centre and radius. 3. Solve mathematical problem related to circle. Objectives:

6. Wheel Circle X Y O Centre Radius

7. A circle is the locus of all points equidistant from a fixed point. The fixed point is called the centre of the circle and the constant distance its radius. O(h, k) A r If the centre of the circle is O (h, k) and radius OA=r then the equation of the circle is

8. General Equation of Circle Then centre=(-g, -f) and radius OA = O(-g,-f ) A

9. Single Work 1. Write down the general equation of circle. 2. Determine the centre and radius of the circle

10. Solution: (Single Work) 1. 2. Centre is ( 3, 2) and radius is 3

11. Q. Find the equation of the circle whose centre is at the point (7, 2) and which passes through the centre of the circle Solution: centre of the given circle is (3, 5) and radius is The equation of circle is

12. Group Work: Q. A circle whose centre is (-4, -5) and passes through the origin. Find the equation of the circle.

13. Solution:(Group Work) Centre= The equation of circle is

14. Evaluation 1. Write down the general equation of circle. 2. Find the centre and radius of the circle

15. 1. Find the equation of the circle whose centre is(3, 5)and radius is 10 units. 2. Find the centre and radius of the circle Home Work

16. Thank you