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महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

Show that the equation 3x2 + 3y2 + 12x + 18y − 11 = 0 represents a circle

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प्रश्न

Show that the equation 3x2 + 3y2 + 12x + 18y − 11 = 0 represents a circle

बेरीज
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उत्तर

Given equation is

3x2 + 3y2 + 12x + 18y − 11 = 0

Dividing throughout by 3, we get

`x^2 + y^2 + 4x + 6y - 11/3` = 0

Comparing this equation with

x2 + y2 + 2gx + 2fy + c = 0, we get

2g = 4, 2f = 6, c = `-11/3`

∴ g = 2, f = 3, c = `-11/3`

Now, g2 + f2 – c = `(2)^2 + (3)^2 - (-11/3)`

= `4 + 9 + 11/3`

= `50/3 > 0`

∴ The given equation represents a circle.

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पाठ 6: Circle - Exercise 6.2 [पृष्ठ १३२]

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