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If the slope of the line given by a^2x^2...

If the slope of the line given by `a^2x^2+2hxy+b^2y^2=0` be three times of the other , then h is equal to

A

(a) `2sqrt(3)ab`

B

(b) `-2sqrt(3)ab`

C

(c) `(2)/(sqrt(3))ab`

D

(d) `-(2)/(sqrt(3)) ab`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to follow these steps: ### Step 1: Identify the equation of the pair of lines The given equation is: \[ a^2x^2 + 2hxy + b^2y^2 = 0 \] This represents a pair of straight lines. ### Step 2: Use the properties of slopes For a pair of lines given by the equation \( Ax^2 + 2Bxy + Cy^2 = 0 \), the slopes \( m_1 \) and \( m_2 \) can be found using the formulas: 1. \( m_1 + m_2 = -\frac{2h}{b^2} \) 2. \( m_1 \cdot m_2 = \frac{a^2}{b^2} \) ### Step 3: Set up the relationship between the slopes According to the problem, one slope is three times the other: \[ m_2 = 3m_1 \] ### Step 4: Substitute \( m_2 \) in the sum of slopes equation Substituting \( m_2 \) into the first equation: \[ m_1 + 3m_1 = -\frac{2h}{b^2} \] This simplifies to: \[ 4m_1 = -\frac{2h}{b^2} \] From this, we can express \( m_1 \): \[ m_1 = -\frac{h}{2b^2} \] ### Step 5: Substitute \( m_1 \) into the product of slopes equation Now, substituting \( m_1 \) into the second equation: \[ m_1 \cdot m_2 = \frac{a^2}{b^2} \] Substituting \( m_2 = 3m_1 \): \[ m_1 \cdot (3m_1) = \frac{a^2}{b^2} \] This gives: \[ 3m_1^2 = \frac{a^2}{b^2} \] ### Step 6: Substitute the value of \( m_1 \) Now substitute \( m_1 = -\frac{h}{2b^2} \): \[ 3\left(-\frac{h}{2b^2}\right)^2 = \frac{a^2}{b^2} \] This simplifies to: \[ 3\left(\frac{h^2}{4b^4}\right) = \frac{a^2}{b^2} \] Multiplying both sides by \( 4b^4 \): \[ 3h^2 = 4a^2b^2 \] ### Step 7: Solve for \( h \) Now, we can solve for \( h \): \[ h^2 = \frac{4a^2b^2}{3} \] Taking the square root: \[ h = \frac{2ab}{\sqrt{3}} \] ### Final Answer Thus, the value of \( h \) is: \[ h = \frac{2ab}{\sqrt{3}} \] ---
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