Home
Class 12
MATHS
A variable plane is at constant distance...

A variable plane is at constant distance 3 from origin and meets the axis in `X,Y,Z` planes through `X,Y,Z` parallel to coordinate planes are made. If `P`be the point of intersection of above made planes, given `P(alpha, beta, gamma)` then `(alpha beta gamma)/(sqrt(alpha^(2)beta^(2)+beta^(2)gamma^(2)+gamma^(2)alpha^(2)))=?`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will derive the necessary equations and find the required value. ### Step 1: Understand the equation of the plane The equation of a plane at a distance \( d \) from the origin can be expressed as: \[ \frac{x}{A} + \frac{y}{B} + \frac{z}{C} = 1 \] where \( A, B, C \) are the intercepts on the x, y, and z axes respectively. ### Step 2: Use the distance formula The distance \( D \) from the origin (0, 0, 0) to the plane is given by: \[ D = \frac{|Ax_1 + By_1 + Cz_1 + D|}{\sqrt{A^2 + B^2 + C^2}} \] For our case, since the plane is at a constant distance of 3 from the origin, we have: \[ 3 = \frac{|0 + 0 + 0 + D|}{\sqrt{A^2 + B^2 + C^2}} \] This simplifies to: \[ |D| = 3\sqrt{A^2 + B^2 + C^2} \] ### Step 3: Set up the plane equation Assuming the plane equation is: \[ \frac{x}{A} + \frac{y}{B} + \frac{z}{C} = 1 \] We can rearrange it to: \[ x + \frac{yB}{A} + \frac{zC}{A} - A = 0 \] This implies \( D = -A \). ### Step 4: Substitute into the distance equation Substituting \( D = -A \) into the distance equation gives: \[ |-A| = 3\sqrt{A^2 + B^2 + C^2} \] Thus: \[ A = 3\sqrt{A^2 + B^2 + C^2} \] ### Step 5: Square both sides Squaring both sides results in: \[ A^2 = 9(A^2 + B^2 + C^2) \] Rearranging gives: \[ A^2(1 - 9) = 9(B^2 + C^2) \] \[ -8A^2 = 9(B^2 + C^2) \] This implies: \[ \frac{1}{A^2} + \frac{1}{B^2} + \frac{1}{C^2} = \frac{1}{9} \] ### Step 6: Express in terms of \( \alpha, \beta, \gamma \) Let \( \alpha = A, \beta = B, \gamma = C \). Then: \[ \frac{1}{\alpha^2} + \frac{1}{\beta^2} + \frac{1}{\gamma^2} = \frac{1}{9} \] ### Step 7: Find the required expression We need to find: \[ \frac{\alpha \beta \gamma}{\sqrt{\alpha^2 \beta^2 + \beta^2 \gamma^2 + \gamma^2 \alpha^2}} \] From the previous result, we can express: \[ \alpha^2 \beta^2 \gamma^2 = \frac{1}{\frac{1}{\alpha^2} + \frac{1}{\beta^2} + \frac{1}{\gamma^2}} = 9 \] Thus, \( \alpha \beta \gamma = 3 \). ### Step 8: Substitute back into the expression Now we substitute back: \[ \frac{3}{\sqrt{\alpha^2 \beta^2 + \beta^2 \gamma^2 + \gamma^2 \alpha^2}} = 3 \] ### Conclusion Thus, the final answer is: \[ \frac{\alpha \beta \gamma}{\sqrt{\alpha^2 \beta^2 + \beta^2 \gamma^2 + \gamma^2 \alpha^2}} = 3 \]

To solve the problem step by step, we will derive the necessary equations and find the required value. ### Step 1: Understand the equation of the plane The equation of a plane at a distance \( d \) from the origin can be expressed as: \[ \frac{x}{A} + \frac{y}{B} + \frac{z}{C} = 1 \] where \( A, B, C \) are the intercepts on the x, y, and z axes respectively. ...
Promotional Banner

Similar Questions

Explore conceptually related problems

The reflection of the point P (alpha, beta, gamma) in the xy-plane is

If p''(x) has real roots alpha,beta,gamma . Then , [alpha]+[beta]+[gamma] is

Determine the values of alpha ,beta , gamma when [{:( 0, 2beta, gamma),( alpha ,beta, -gamma),( alpha ,-beta, gamma):}] is orthogonal.

If alpha , beta , gamma are the roots of x^3 + px^2+qx -r=0 then alpha^2 + beta^2 + gamma^2 =

If a line makes anles alpha, beta, gamma with the coordinate axes, porve that sin^2alpha+sin^2beta+sin^2gamma=2

The distance of the point P ( alpha, beta , gamma) from x-axis is

If vec(A) makes an angle alpha, beta and gamma from x,y and z axis respectively then sin^(2)alpha+sin^(2) beta+sin^(2) gamma=

If 2x^(3) + 3x^(2) + 5x +6=0 has roots alpha, beta, gamma then find alpha + beta + gamma, alphabeta + betagamma + gammaalpha and alpha beta gamma

If alpha,beta,gamma are the roots of the equation x^3 + 4x +1=0 then (alpha+beta)^(-1)+(beta+gamma)^(-1)+(gamma+alpha)^(-1)=

If 2 sin alphacos beta sin gamma=sinbeta sin(alpha+gamma),then tan alpha,tan beta and gamma are in