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Let pi(1)and pi(2) be two planes and L b...

Let `pi_(1)and pi_(2)` be two planes and `L` be a line such that
`pi_(1): x + 2y + 3z = 14`
`pi_(2) : 2x - y +3z = 27`
`L : (x+1)/2=(y+1)/3=(z+1)/4`
If the line `L` meets the plane `pi_(1)` in `P(alpha, beta, gamma),`
Then `alpha^(2)+beta^(2)+gamma^(2)` is equal to:

A

(a) `2`

B

(b) `14`

C

(c) `28`

D

(d) `29`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the point \( P(\alpha, \beta, \gamma) \) where the line \( L \) intersects the plane \( \pi_1 \), and then calculate \( \alpha^2 + \beta^2 + \gamma^2 \). ### Step-by-Step Solution: 1. **Define the Line and Planes**: - The line \( L \) is given by: \[ \frac{x + 1}{2} = \frac{y + 1}{3} = \frac{z + 1}{4} \] - The plane \( \pi_1 \) is defined by: \[ x + 2y + 3z = 14 \] 2. **Parameterize the Line**: - Let \( \frac{x + 1}{2} = \frac{y + 1}{3} = \frac{z + 1}{4} = \lambda \) (where \( \lambda \) is a parameter). - From this, we can express \( x, y, z \) in terms of \( \lambda \): \[ x = 2\lambda - 1, \quad y = 3\lambda - 1, \quad z = 4\lambda - 1 \] 3. **Substitute into the Plane Equation**: - Substitute \( x, y, z \) into the plane equation \( \pi_1 \): \[ (2\lambda - 1) + 2(3\lambda - 1) + 3(4\lambda - 1) = 14 \] - Simplifying this: \[ 2\lambda - 1 + 6\lambda - 2 + 12\lambda - 3 = 14 \] \[ 20\lambda - 6 = 14 \] \[ 20\lambda = 20 \implies \lambda = 1 \] 4. **Find Coordinates \( \alpha, \beta, \gamma \)**: - Substitute \( \lambda = 1 \) back into the parameterized equations: \[ \alpha = 2(1) - 1 = 1 \] \[ \beta = 3(1) - 1 = 2 \] \[ \gamma = 4(1) - 1 = 3 \] 5. **Calculate \( \alpha^2 + \beta^2 + \gamma^2 \)**: - Now compute: \[ \alpha^2 + \beta^2 + \gamma^2 = 1^2 + 2^2 + 3^2 = 1 + 4 + 9 = 14 \] ### Conclusion: The value of \( \alpha^2 + \beta^2 + \gamma^2 \) is \( 14 \).
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