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If the slopes of the lines 3x^(2) + 2hxy...

If the slopes of the lines `3x^(2) + 2hxy + 4y^(2)=0` are in the ration `3:1`, then h equals

A

`1//4`

B

-4

C

0

D

`-1//4`

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of \( h \) such that the slopes of the lines given by the equation \( 3x^2 + 2hxy + 4y^2 = 0 \) are in the ratio \( 3:1 \), we can follow these steps: ### Step-by-Step Solution: 1. **Identify the coefficients**: The given equation is of the form \( ax^2 + 2hxy + by^2 = 0 \). Here, we have: - \( a = 3 \) - \( b = 4 \) - \( 2h = 2h \) 2. **Use the formulas for the sum and product of slopes**: For the general conic equation \( ax^2 + 2hxy + by^2 = 0 \): - The sum of the slopes \( m_1 + m_2 \) is given by: \[ m_1 + m_2 = -\frac{2h}{b} \] - The product of the slopes \( m_1 m_2 \) is given by: \[ m_1 m_2 = \frac{a}{b} \] 3. **Substitute the values of \( a \) and \( b \)**: - From the product of slopes: \[ m_1 m_2 = \frac{3}{4} \] - From the sum of slopes: \[ m_1 + m_2 = -\frac{2h}{4} = -\frac{h}{2} \] 4. **Express the slopes in terms of a single variable**: Since the slopes are in the ratio \( 3:1 \), we can let: \[ m_1 = 3k \quad \text{and} \quad m_2 = k \] where \( k \) is a constant. 5. **Set up equations using the sum and product**: - From the product: \[ (3k)(k) = \frac{3}{4} \implies 3k^2 = \frac{3}{4} \implies k^2 = \frac{1}{4} \implies k = \frac{1}{2} \] - Thus, we have: \[ m_2 = k = \frac{1}{2} \quad \text{and} \quad m_1 = 3k = \frac{3}{2} \] 6. **Substituting back to find \( h \)**: - Now substitute \( m_1 \) and \( m_2 \) into the sum equation: \[ m_1 + m_2 = \frac{3}{2} + \frac{1}{2} = 2 \] - Set this equal to the expression for the sum of slopes: \[ 2 = -\frac{h}{2} \] - Solving for \( h \): \[ -\frac{h}{2} = 2 \implies h = -4 \] ### Final Answer: Thus, the value of \( h \) is \( -4 \).
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