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The equation of the straigh lines throug...

The equation of the straigh lines through the point `(x_(1),y_(1))` and parallel to the lines given by `ax^(2)+2xy+ay^(2)=0`, is

A

`a(y-y_(1))^(2)+2h(x-x_(1))(y-y_(1))+b(x-x_(1))^(2)=0`

B

`a(y-y_(1))^(2)-2h(x-x_(1))(y-y_(1))+b(x-x_(1))^(2)=0`

C

`b(y-y_(1))^(2)+2h(x-x_(1))(y-y_(1))+a(x-x_(1))^(2)=0`

D

none of these

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The correct Answer is:
To find the equation of the straight lines through the point \((x_1, y_1)\) and parallel to the lines given by the equation \(ax^2 + 2xy + ay^2 = 0\), we can follow these steps: ### Step 1: Understand the given equation The equation \(ax^2 + 2xy + ay^2 = 0\) represents a pair of straight lines through the origin. We need to find lines that are parallel to these lines and pass through the point \((x_1, y_1)\). ### Step 2: Rewrite the equation in terms of shifted coordinates To find the equation of the lines parallel to the given lines and passing through \((x_1, y_1)\), we can shift the origin to this point. We can substitute \(x = X + x_1\) and \(y = Y + y_1\) into the original equation, where \(X\) and \(Y\) are the new coordinates. ### Step 3: Substitute into the original equation Substituting \(x = X + x_1\) and \(y = Y + y_1\) into the equation \(ax^2 + 2xy + ay^2 = 0\), we get: \[ a(X + x_1)^2 + 2(X + x_1)(Y + y_1) + a(Y + y_1)^2 = 0 \] ### Step 4: Expand the equation Expanding this equation: \[ a(X^2 + 2Xx_1 + x_1^2) + 2(XY + Xy_1 + Yx_1 + x_1y_1) + a(Y^2 + 2Yy_1 + y_1^2) = 0 \] This simplifies to: \[ aX^2 + 2XY + aY^2 + 2Xx_1 + 2Yy_1 + ax_1^2 + 2x_1y_1 + ay_1^2 = 0 \] ### Step 5: Rearranging the equation Rearranging the equation gives us: \[ aX^2 + 2XY + aY^2 + 2Xx_1 + 2Yy_1 + (ax_1^2 + 2x_1y_1 + ay_1^2) = 0 \] Since we want the lines through \((x_1, y_1)\), we can set the constant term to zero: \[ aX^2 + 2XY + aY^2 + 2Xx_1 + 2Yy_1 = 0 \] ### Step 6: Final form of the equation The final equation of the straight lines through the point \((x_1, y_1)\) and parallel to the lines given by \(ax^2 + 2xy + ay^2 = 0\) is: \[ a(x - x_1)^2 + 2(x - x_1)(y - y_1) + a(y - y_1)^2 = 0 \] ### Conclusion Thus, the required equation is: \[ a(x - x_1)^2 + 2(x - x_1)(y - y_1) + a(y - y_1)^2 = 0 \]

To find the equation of the straight lines through the point \((x_1, y_1)\) and parallel to the lines given by the equation \(ax^2 + 2xy + ay^2 = 0\), we can follow these steps: ### Step 1: Understand the given equation The equation \(ax^2 + 2xy + ay^2 = 0\) represents a pair of straight lines through the origin. We need to find lines that are parallel to these lines and pass through the point \((x_1, y_1)\). ### Step 2: Rewrite the equation in terms of shifted coordinates To find the equation of the lines parallel to the given lines and passing through \((x_1, y_1)\), we can shift the origin to this point. We can substitute \(x = X + x_1\) and \(y = Y + y_1\) into the original equation, where \(X\) and \(Y\) are the new coordinates. ...
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OBJECTIVE RD SHARMA ENGLISH-PAIR OF STRAIGHT LINES-Section I - Solved Mcqs
  1. If the distance of a point (x(1),y(1)) from each of the two straight l...

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  2. The equation of two straight lines through the point (x(1),y(1)) and p...

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  3. The equation of the straigh lines through the point (x(1),y(1)) and pa...

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  4. The triangle formed by the lines whose combined equation is (y^2 - 4xy...

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  5. Find the combined equation of the pair of lines through the point (1, ...

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  6. The equation x^(3)+ax^(2)y+bxy^(2)+y^(3)=0 represents three straight l...

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  7. The combined equation of the lines L(1) and L(2) is 2x^(2)+6xy+y^(2)=0...

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  8. The lines represented by x^(2)+2lambda xy+2y^(2)=0 and the lines repre...

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  9. Prove that the equation m (x^3-3xy^2)+y^3-3x^2y=0 represents three str...

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  10. If the equation x^(4)+bx^(3)y+cx^(2)y^(2)+dxy^(3)+ey^(4)=0 represent t...

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  11. The equation x^(3)+x^(2)y-xy^(2)-y^(3)=0 represents three straight lin...

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  12. If one of the lines of my^(2)+(1-m^(2))xy-mx^(2)=0 is a bisector of th...

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  13. The equation x^2 - 3xy+ lambday^2 + 3x - 5y + 2 = 0 where lambda is a ...

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  14. If the line y = mx bisects the angle between the lines ax^2 + 2h xy ...

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  15. Two pairs of straight lines have the equations y^(2)+xy-12x^(2)=0andax...

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  16. The point of intersection of the pair of straight lines given by 6x^(2...

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  17. The straight lines represented by x^2+m x y-2y^2+3y-1=0 meet at (a) (-...

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  18. The square of the distance between the origin and the point of interse...

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  19. The centroid of the triangle whose three sides are given by the combin...

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  20. If first degree terms and constant term are to be removed from the equ...

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