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The co-ordinates of foci of an ellipse 3...

The co-ordinates of foci of an ellipse `3x^(2)+4y^(2)+12x+16y-8=0` is :

A

`(pm sqrt(3)-2,-2)`

B

`(-2, -2) `

C

`(2-sqrt(3), pm2)`

D

`(2+sqrt(3), -2)`

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To find the coordinates of the foci of the ellipse given by the equation \(3x^2 + 4y^2 + 12x + 16y - 8 = 0\), we will follow these steps: ### Step 1: Rearrange the equation We start with the equation: \[ 3x^2 + 4y^2 + 12x + 16y - 8 = 0 \] Rearranging gives: \[ 3x^2 + 12x + 4y^2 + 16y = 8 \] ### Step 2: Complete the square for \(x\) and \(y\) For the \(x\) terms: \[ 3(x^2 + 4x) = 3[(x + 2)^2 - 4] = 3(x + 2)^2 - 12 \] For the \(y\) terms: \[ 4(y^2 + 4y) = 4[(y + 2)^2 - 4] = 4(y + 2)^2 - 16 \] Substituting these back into the equation gives: \[ 3(x + 2)^2 - 12 + 4(y + 2)^2 - 16 = 8 \] Simplifying this: \[ 3(x + 2)^2 + 4(y + 2)^2 - 28 = 8 \] \[ 3(x + 2)^2 + 4(y + 2)^2 = 36 \] ### Step 3: Divide by 36 to get the standard form Dividing the entire equation by 36 gives: \[ \frac{(x + 2)^2}{12} + \frac{(y + 2)^2}{9} = 1 \] This is now in the standard form of an ellipse: \[ \frac{(x - h)^2}{a^2} + \frac{(y - k)^2}{b^2} = 1 \] where \(h = -2\), \(k = -2\), \(a^2 = 12\), and \(b^2 = 9\). ### Step 4: Identify \(a\) and \(b\) From the above, we have: \[ a = \sqrt{12} = 2\sqrt{3}, \quad b = \sqrt{9} = 3 \] ### Step 5: Calculate the eccentricity \(e\) The eccentricity \(e\) is given by: \[ e = \sqrt{1 - \frac{b^2}{a^2}} = \sqrt{1 - \frac{9}{12}} = \sqrt{\frac{1}{4}} = \frac{1}{2} \] ### Step 6: Find the coordinates of the foci The foci of the ellipse are located at: \[ (h \pm ae, k) = (-2 \pm (2\sqrt{3} \cdot \frac{1}{2}), -2) = (-2 \pm \sqrt{3}, -2) \] Thus, the coordinates of the foci are: \[ (-2 + \sqrt{3}, -2) \quad \text{and} \quad (-2 - \sqrt{3}, -2) \] ### Final Answer The coordinates of the foci of the ellipse are: \[ (-2 + \sqrt{3}, -2) \quad \text{and} \quad (-2 - \sqrt{3}, -2) \]

To find the coordinates of the foci of the ellipse given by the equation \(3x^2 + 4y^2 + 12x + 16y - 8 = 0\), we will follow these steps: ### Step 1: Rearrange the equation We start with the equation: \[ 3x^2 + 4y^2 + 12x + 16y - 8 = 0 \] Rearranging gives: ...
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