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If the equation ax^(2)+2hxy+by^(2)+2gx...

If the equation
`ax^(2)+2hxy+by^(2)+2gx+2fy+c=0`
represents two straights lines, then the product of the perpendicular from the origin on these straight lines, is

A

`(c)/(sqrt((a-b)^(2)-4h^(2)))`

B

`(c)/(sqrt((a-b)^(2)+4h^(2)))`

C

`(c)/(sqrt((a+b)^(2)-4h^(2)))`

D

none of these

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The correct Answer is:
To solve the problem, we need to find the product of the perpendicular distances from the origin to the two straight lines represented by the given equation: \[ ax^2 + 2hxy + by^2 + 2gx + 2fy + c = 0 \] ### Step-by-Step Solution: 1. **Understand the Equation**: The given equation represents a pair of straight lines if the determinant formed by the coefficients is zero. The general form of the equation is: \[ ax^2 + 2hxy + by^2 + 2gx + 2fy + c = 0 \] 2. **Identify the Lines**: We can express the equation in terms of two lines \( L_1 \) and \( L_2 \): \[ L_1: l_1 x + m_1 y + n_1 = 0 \] \[ L_2: l_2 x + m_2 y + n_2 = 0 \] 3. **Coefficients Comparison**: By comparing coefficients of the original equation with the expanded form of the product of the two lines, we have: - \( l_1 l_2 = a \) - \( m_1 m_2 = b \) - \( n_1 n_2 = c \) - \( l_1 m_2 + l_2 m_1 = 2h \) - \( l_1 n_2 + l_2 n_1 = 2g \) - \( m_1 n_2 + m_2 n_1 = 2f \) 4. **Formula for Product of Perpendicular Distances**: The product of the perpendicular distances from the origin to the two lines can be calculated using the formula: \[ \text{Product of perpendiculars} = \frac{n_1 n_2}{\sqrt{(l_1^2 + m_1^2)(l_2^2 + m_2^2)}} \] 5. **Substituting Values**: From the coefficients, we know: - \( n_1 n_2 = c \) - \( l_1 l_2 = a \) - \( m_1 m_2 = b \) - \( l_1 m_2 + l_2 m_1 = 2h \) Therefore, we can express the denominator: \[ \sqrt{(l_1^2 + m_1^2)(l_2^2 + m_2^2)} = \sqrt{l_1^2 l_2^2 + m_1^2 m_2^2 + (l_1 m_2 + l_2 m_1)^2 - 2l_1 l_2 m_1 m_2} \] Substituting the known values: \[ = \sqrt{a^2 + b^2 + 4h^2 - 2ab} \] 6. **Final Expression**: Thus, the product of the perpendicular distances from the origin to the two lines is: \[ \frac{c}{\sqrt{(a - b)^2 + 4h^2}} \] ### Conclusion: The product of the perpendicular distances from the origin to the two straight lines represented by the equation is given by: \[ \frac{c}{\sqrt{(a - b)^2 + 4h^2}} \]

To solve the problem, we need to find the product of the perpendicular distances from the origin to the two straight lines represented by the given equation: \[ ax^2 + 2hxy + by^2 + 2gx + 2fy + c = 0 \] ### Step-by-Step Solution: 1. **Understand the Equation**: The given equation represents a pair of straight lines if the determinant formed by the coefficients is zero. The general form of the equation is: ...
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OBJECTIVE RD SHARMA ENGLISH-PAIR OF STRAIGHT LINES-Chapter Test
  1. If the equation ax^(2)+2hxy+by^(2)+2gx+2fy+c=0 represents two str...

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  2. If the lines given by ax^(2)+2hxy+by^(2)=0 are equally inclined to the...

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  3. The equation to the striaght lines passing through the origin and maki...

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  4. Prove that the limiting points of the system x^(2)+y^(2)+2gx+c+lamda(x...

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  5. If the area of the triangle formed by the pair of lines 8x^2 - 6xy + y...

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  6. The equation to the pair of straight lines bisecting the angles betwe...

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  7. If the pair of lines sqrt(3)x^2-4x y+sqrt(3)y^2=0 is rotated about the...

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  8. Show that if two of the lines ax^3+bx^2y+cxy^2+dy^3=0 (a ne 0) make co...

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  9. If the pairs of straight lines ax^2+2hxy-ay^2=0 and bx^2+2gxy-by^2=0 b...

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  10. The equation a^2x^2+2h(a+b)x y+b^2y^2=0 and a x^2+2h x y+b y^2=0 repre...

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  11. If (x^(2))/(a) + (y^(2))/(b) + (2xy)/(h) =0 represent pair of straig...

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  12. If the lines represented by the equation ax^(2)+2hxy+by^(2)+2gx+2fy+c=...

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  13. The distance between the two lines represented by the  sides of an equ...

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  14. The equation of the image of the lines y=|x| in the line mirror x = 2 ...

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  15. If the equation 3x^(2)+xy-y^(2)-3x+6y+k=0 represents a pair of straigh...

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  16. The equation of second degree x^2+2sqrt2xy+2y^2+4x+4sqrt2y+1=0 represe...

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  17. The value of lambda for which the equation x^2-y^2 - x - lambda y - ...

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  18. Distance between the pair of lines represented by the equation x^(2)-6...

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

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