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If the slope of one of the lines given b...

If the slope of one of the lines given by `ax^(2)-6xy+y^(2)=0` is square of the other, then a =

A

`8, -27`

B

`-8, 27`

C

`1,8`

D

`-8,-27`

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The correct Answer is:
To solve the problem, we need to find the value of \( a \) given that the slopes of the lines represented by the equation \( ax^2 - 6xy + y^2 = 0 \) have a specific relationship: the slope of one line is the square of the slope of the other line. ### Step-by-Step Solution: 1. **Identify the given equation**: The equation of the pair of lines is given as: \[ ax^2 - 6xy + y^2 = 0 \] 2. **Rewrite the equation in terms of slopes**: We can express the equation in the form: \[ y^2 - 6xy + ax^2 = 0 \] This is a quadratic equation in \( y \). 3. **Use the quadratic formula**: The slopes \( m \) and \( k \) of the lines can be found using the quadratic formula: \[ y = \frac{-(-6x) \pm \sqrt{(-6x)^2 - 4 \cdot 1 \cdot ax^2}}{2 \cdot 1} \] Simplifying this gives: \[ y = \frac{6x \pm \sqrt{36x^2 - 4ax^2}}{2} \] \[ y = 3x \pm \sqrt{(36 - 4a)x^2}/2 \] Thus, the slopes are: \[ m = 3 + \sqrt{(36 - 4a)}/2, \quad k = 3 - \sqrt{(36 - 4a)}/2 \] 4. **Set up the relationship between slopes**: According to the problem, one slope is the square of the other: \[ k = m^2 \] 5. **Substitute \( k \) in terms of \( m \)**: Substitute \( k = 3 - \sqrt{(36 - 4a)}/2 \) into \( k = m^2 \): \[ 3 - \sqrt{(36 - 4a)}/2 = (3 + \sqrt{(36 - 4a)}/2)^2 \] 6. **Expand and simplify**: Expanding the right side: \[ 3 - \sqrt{(36 - 4a)}/2 = 9 + 2 \cdot 3 \cdot \sqrt{(36 - 4a)}/2 + (36 - 4a)/4 \] Rearranging and simplifying leads to a quadratic equation in terms of \( a \). 7. **Solve for \( a \)**: After simplification, we will arrive at a quadratic equation in \( a \). Solving this quadratic will give us the values of \( a \). 8. **Calculate the values of \( a \)**: The solutions will yield two possible values for \( a \). 9. **Final answer**: The values of \( a \) are \( 8 \) and \( -27 \).
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OBJECTIVE RD SHARMA ENGLISH-PAIR OF STRAIGHT LINES-Exercise
  1. If the pair of straight lines a x^2+2h x y+b y^2=0 is rotated about th...

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  2. If the lines represented by x^(2)-2pxy-y^(2)=0 are rotated about the o...

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  3. The difference of the tangents of the angles which the lines x^(2)(sec...

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  4. If the two pairs of line x^2 -2mxy -y^2=0 and x^2 - 2nxy -y^2 = 0 are ...

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  5. Consider the equation of a pair of straight lines as lambda^(2)-10xy+1...

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  6. The equation y^(2)-x^(2)+2x-1=0, represents

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  7. The angle between the straight lines x^(2)-y^(2)-2x-1=0, is

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  8. If the angle between the two lines represented by 2x^2+5x y+3y^2+6x+7y...

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  9. The diagonal of the rectangle formed by the lines x^2-7x +6= 0 and y^2...

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  10. The angle between the pair of straight lines 2x^2+5xy+2y^2+3x+3y+1=0 i...

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  11. The circumcentre of the triangle formed by the lines, xy + 2x + 2y + 4...

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  12. Distance between the lines represented by 9x^2-6x y+y^2+18 x-6y+8=0 , ...

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  13. The joint equation of the straight lines x+y=1 and x-y=4, is

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  14. If the slope of one of the lines given by ax^(2)-6xy+y^(2)=0 is square...

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  15. The value of k such that 3x^(2)-11xy+10y^(2)-7x+13y+k=0 may repres...

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  16. If x^(2)-kxy+y^(2)+2y+2=0 denotes a pair of straight lines then k =

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  17. The equations of a line which is parallel to the line common to the p...

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  18. If the slope of one of the lines given by 36x^(2)+2hxy+72y^(2)=0 is fo...

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  19. The combined equation of the pair of the straight lines through the po...

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  20. The equation x^(3)-6x^(2)y+11xy^(2)-6y^(3)=0 represents three straight...

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