Home
Class 12
MATHS
Lines whose equation are (x-3)/2=(y-2)/3...

Lines whose equation are `(x-3)/2=(y-2)/3=(z-1)/(lamda)` and `(x-2)/3=(y-3)/2=(z-2)/3` lie in same plane, then.
Angle between the plane containing both lines and the plane `4x+y+2z=0` is

A

`(pI)/(3)`

B

`(pi)/(2)`

C

`(pi)/(6)`

D

`cos^(-1)((1)/(sqrt(186)))`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine the angle between the plane containing the two given lines and the plane defined by the equation \(4x + y + 2z = 0\). ### Step 1: Write the equations of the lines in vector form. The first line is given by: \[ \frac{x - 3}{2} = \frac{y - 2}{3} = \frac{z - 1}{\lambda} \] This can be expressed in vector form as: \[ \vec{r_1} = \begin{pmatrix} 3 \\ 2 \\ 1 \end{pmatrix} + t \begin{pmatrix} 2 \\ 3 \\ \lambda \end{pmatrix} \] The second line is given by: \[ \frac{x - 2}{3} = \frac{y - 3}{2} = \frac{z - 2}{3} \] This can be expressed in vector form as: \[ \vec{r_2} = \begin{pmatrix} 2 \\ 3 \\ 2 \end{pmatrix} + s \begin{pmatrix} 3 \\ 2 \\ 3 \end{pmatrix} \] ### Step 2: Identify the direction vectors and points on the lines. From the equations, we can identify: - For line 1: - Point \(A_1 = (3, 2, 1)\) - Direction vector \(b_1 = (2, 3, \lambda)\) - For line 2: - Point \(A_2 = (2, 3, 2)\) - Direction vector \(b_2 = (3, 2, 3)\) ### Step 3: Find the vector connecting the two points. The vector \(A_2 - A_1\) is: \[ A_2 - A_1 = \begin{pmatrix} 2 \\ 3 \\ 2 \end{pmatrix} - \begin{pmatrix} 3 \\ 2 \\ 1 \end{pmatrix} = \begin{pmatrix} -1 \\ 1 \\ 1 \end{pmatrix} \] ### Step 4: Use the condition for coplanarity. For the lines to lie in the same plane, the scalar triple product of the vectors \(A_2 - A_1\), \(b_1\), and \(b_2\) must be zero: \[ (A_2 - A_1) \cdot (b_1 \times b_2) = 0 \] ### Step 5: Calculate the cross product \(b_1 \times b_2\). The cross product can be calculated using the determinant: \[ b_1 \times b_2 = \begin{vmatrix} \hat{i} & \hat{j} & \hat{k} \\ 2 & 3 & \lambda \\ 3 & 2 & 3 \end{vmatrix} \] Calculating this determinant: \[ = \hat{i} \begin{vmatrix} 3 & \lambda \\ 2 & 3 \end{vmatrix} - \hat{j} \begin{vmatrix} 2 & \lambda \\ 3 & 3 \end{vmatrix} + \hat{k} \begin{vmatrix} 2 & 3 \\ 3 & 2 \end{vmatrix} \] \[ = \hat{i} (9 - 2\lambda) - \hat{j} (6 - 3\lambda) + \hat{k} (4 - 9) \] \[ = (9 - 2\lambda) \hat{i} - (6 - 3\lambda) \hat{j} - 5 \hat{k} \] ### Step 6: Set up the equation for coplanarity. Now we compute the dot product with \(A_2 - A_1\): \[ \begin{pmatrix} -1 \\ 1 \\ 1 \end{pmatrix} \cdot \begin{pmatrix} 9 - 2\lambda \\ -(6 - 3\lambda) \\ -5 \end{pmatrix} = 0 \] This gives: \[ -1(9 - 2\lambda) + 1(-6 + 3\lambda) - 5 = 0 \] \[ -9 + 2\lambda - 6 + 3\lambda - 5 = 0 \] \[ 5\lambda - 20 = 0 \implies \lambda = 4 \] ### Step 7: Find the normal vector of the plane containing both lines. The direction vectors are: - \(b_1 = (2, 3, 4)\) - \(b_2 = (3, 2, 3)\) The normal vector \(n\) of the plane containing both lines is \(b_1 \times b_2\): \[ b_1 \times b_2 = \begin{pmatrix} 9 - 8 \\ -6 + 12 \\ -5 \end{pmatrix} = (1, 6, -5) \] ### Step 8: Find the normal vector of the given plane. The normal vector of the plane \(4x + y + 2z = 0\) is: \[ n_2 = (4, 1, 2) \] ### Step 9: Find the angle between the two planes. The cosine of the angle \(\theta\) between the two planes can be found using the dot product: \[ \cos \theta = \frac{n_1 \cdot n_2}{|n_1| |n_2|} \] Calculating the dot product: \[ n_1 \cdot n_2 = (1)(4) + (6)(1) + (-5)(2) = 4 + 6 - 10 = 0 \] Since the dot product is zero, the angle \(\theta\) is: \[ \theta = \frac{\pi}{2} \] ### Final Answer: The angle between the plane containing both lines and the plane \(4x + y + 2z = 0\) is \(\frac{\pi}{2}\) radians. ---

To solve the problem, we need to determine the angle between the plane containing the two given lines and the plane defined by the equation \(4x + y + 2z = 0\). ### Step 1: Write the equations of the lines in vector form. The first line is given by: \[ \frac{x - 3}{2} = \frac{y - 2}{3} = \frac{z - 1}{\lambda} \] ...
Promotional Banner

Topper's Solved these Questions

  • TEST PAPERS

    RESONANCE ENGLISH|Exercise PART : 1MATHEMATICS SEC - 1|1 Videos
  • TEST PAPERS

    RESONANCE ENGLISH|Exercise PART : 1MATHEMATICS|9 Videos
  • TEST PAPER

    RESONANCE ENGLISH|Exercise MATHEMATICS|48 Videos
  • TEST SERIES

    RESONANCE ENGLISH|Exercise MATHEMATICS|132 Videos

Similar Questions

Explore conceptually related problems

Lines whose equation are (x-3)/2=(y-2)/3=(z-1)/(lamda) and (x-2)/3=(y-3)/2=(z-2)/3 lie in same plane, then. The value of sin^(-1)sinlamda is equal to

Two line whose equations are (x-3)/(2)=(y-2)/(3)=(z-1)/(3) and (x-2)/(3)=(y-3)/(2)=(z-2)/(3) find the angle between them

Show that the lines (x-3)/2=(y+1)/(-3)=(z+2)/1 and (x-7)/(-3)=y/1=(z+7)/2 are coplanar. Also find the equation of the plane containing them.

Show that the lines (x+3)/(-3)=y-1/1=(z-5)/5;(x+1)/(-1)=(y-2)/2=(z-5)/5 are coplanar. Also find the equation of the plane containing the lines.

Find the angle between the plane: 2x-y+z=4\ a n d\ x+y+2z=3

The acute angle between the planes 2x-y+z=6 and x+y+2z=3 is

Show that the lines (x+1)/(-3)=(y-3)/2=(z+2)/1\ a n d\ x/1=(y-7)/(-3)=(z+7)/2 are coplanar. Also, find the equation of the plane containing them.

The sine of the angle between the line (x-2)/(3) = (y-3)/(4) = (z-4)/(5) and the plane 2x-2y+z=5 is

Find the angle between the planes 3x+y+2z=1 and 2x-y+z+3 = 0 .

Find the angle between the line (x+1)/2=y/3=(z-3)/6 and the plane 10 x + 2y -11 z = 3 .

RESONANCE ENGLISH-TEST PAPERS-MATHEMATICS
  1. Lines whose equation are (x-3)/2=(y-2)/3=(z-1)/(lamda) and (x-2)/3=(y-...

    Text Solution

    |

  2. The least positive vlaue of the parameter 'a' for which there exist at...

    Text Solution

    |

  3. The locus of the midpoint of a chord of the circle x^2+y^2=4 which sub...

    Text Solution

    |

  4. If f(x)=x + tan x and f si the inverse of g, then g'(x) equals

    Text Solution

    |

  5. Tangents PA and PB are drawn to parabola y^(2)=4x from any arbitrary p...

    Text Solution

    |

  6. If lim(nrarroo) (n.2^(n))/(n(3x-4)^(n)+n.2^(n+1)+2^(n))=1/2 where "n" ...

    Text Solution

    |

  7. Eccentricity of ellipse 2(x-y+1)^(2)+3(x+y+2)^(2)=5 is

    Text Solution

    |

  8. If (tan^(-1)x)^(3)+(tan^(-1)y)^(3)=1-3tan^(-1)x.tan^(-1)y. Then which ...

    Text Solution

    |

  9. If f:RrarrR is a continuous function satisfying f(0)=1 and f(2x)-f(x)=...

    Text Solution

    |

  10. tan^(-1)(sinx)=sin^(-1)(tanx) holds true for

    Text Solution

    |

  11. The function f(x) = (x^(2) - 1)|x^(2) - 3x + 3|+cos (|x|) is not diffe...

    Text Solution

    |

  12. Consider parabola P(1)-=y=x^(2) and P(2)-=y^(2)=-8x and the line L-=lx...

    Text Solution

    |

  13. If the normals at (x(i),y(i)) i=1,2,3,4 to the rectangular hyperbola x...

    Text Solution

    |

  14. Let f(x) = x^(3) - x^(2) + x + 1 and g(x) = {{:(max f(t)",", 0 le t le...

    Text Solution

    |

  15. The sum of the roots of the equation tan^(-1)(x+3)-tan^(-1)(x-3)="sin"...

    Text Solution

    |

  16. For an ellipse having major and minor axis along x and y axes respecti...

    Text Solution

    |

  17. If f:[0,1]rarrR is defined as f(x)={(x^(3)(1-x)"sin"1/(x^(2)) 0ltxle1)...

    Text Solution

    |

  18. If f(x)=root (3)(8x^(3)+mx^(2))-nx such that lim(xrarroo)f(x)=1 then

    Text Solution

    |

  19. For the curve y=4x^3-2x^5, find all the points at which the tangents p...

    Text Solution

    |

  20. Minimum value of (sin^(-1)x)^(2)+(cos^(-1)x)^(2) is greater than

    Text Solution

    |

  21. If y + b = m(1)(x + a) and y + b = m(2)(x+a) are two tangents to the p...

    Text Solution

    |