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Find the centre and radius of the following: x2 + y2 − 2x + 4y − 4 = 0 - Mathematics and Statistics

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प्रश्न

Find the centre and radius of the following:

x2 + y2 − 2x + 4y − 4 = 0

योग

उत्तर

Comparing the equation
x2 + y2 − 2x + 4y − 4 = 0
with the equation
x2 + y2 + 2gx + 2fy + c = 0, we get,

2g= − 2, 2f = 4 and c = − 4

∴ g = − 1, f = 2 and c = − 4

∴ centre of the circle = (− g, − f) = (1, − 2)

and radius of the circle = `sqrt("g"^2 + f^2 - "c"`

= `sqrt((-1)^2 + (2)^2 - (- 4))`

= `sqrt(1 + 4 + 4)`

= 3.

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Different Forms of Equation of a Circle
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 6: Circle - Exercise 6.2 [पृष्ठ १३२]

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