Q1 of 101 Page 24

Find the coordinates of the centre radius of each of the following circle:

x2 + y2 + 6x - 8y - 24 = 0

Given equation of the circle is x2 + y2 + 6x - 8y - 24 = 0 …… (1)



We know that for a circle x2 + y2 + 2ax + 2by + c = 0 ……(2)


⇒ Centre = (- a, - b)


⇒ Radius =


Comparing (1) with (2) we get,


⇒ Centre =


⇒ Centre = (- 3,4)


⇒ Radius =


⇒ Radius =


⇒ Radius = √49


⇒ Radius = 7


∴ The centre and radius of the circle is (- 3,4) and 7.


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If the line 2x – y + 1 = 0 touches the circle at the point (2, 5) and the centre of the circle lies on the line x + y – 9 = 0. Find the equation of the circle.

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Find the coordinates of the centre radius of each of the following circle:

2x2 + 2y2 – 3x + 5y = 7

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Find the coordinates of the centre radius of each of the following circle: