Home
Class 12
MATHS
A vector vecr is inclined at equal angle...

A vector `vecr` is inclined at equal angles to the three axes. If the magnitude of `vecr` is `2sqrt3` units, then find the value of `vecr`.

Text Solution

Verified by Experts

We have `|vecr|=2sqrt3`
Since, `vecr` is equally inclined ot the three axes, `vecr` so dircetion cosines of the unit vector `vecr` will be same.i.e., l=m=n.
We know that,
`l^(2)+m^(2)+n^(2)=1`
`impliesl^(2)+l^(2)+l^(2)=1`
`impliesl^(2)=(1)/(3)`
`impliesl=+-((1)/(sqrt3))`
So, `hatr=+-(1)/(sqrt3)hati+-(1)/(sqrt3)hatj+-(1)/(sqrt3)hatk`
`:.vecr=vecr|vecr|" "[:'vecr=(vecr)/(vec|r|)]`
`=[+-(1)/(sqrt3)hati+-(1)/(sqrt3)hatj+-(1)/(sqrt3)hatk]2sqrt3" "[:'|vecr|=2sqrt3]`
`=+-2hati+-2hatj+-2hatk=+-2(hati+hatj+hatk)`
Promotional Banner

Topper's Solved these Questions

  • THREE DIMENSIONAL GEOMETRY

    NCERT EXEMPLAR|Exercise Three Dimensional Geometry|46 Videos

Similar Questions

Explore conceptually related problems

A vector vecr=aveci+bvecj is equally inclined to both x and y axes. If the magnitude of the vetor is 2 units, then what are the values of a and b respectively?

Find a vector vecr equally inclined to the three axes and whose magnitude is 3 sqrt(3) units.

A vector vecr is equally inclined with the coordinates axes. If the tip of vecr is in the positive octant and |vecr|=6 , then vecr is

There vectors vecP, vecQ and vecR are such that vecP+vecQ+vecR=0 Vectors vecP and vecQ are equal in , magnitude . The magnitude of vector vecR is sqrt2 times the magnitude of either vecP or vecQ . Calculate the angle between these vectors .

A vector vecr is inclined to x-axis at 45^(@) and y-axis at 60^(@) if |vecr| =8 units. Find vecr.

Let vecp2hati+hatj-2hatk, vecq=hati+hatj. If vecr is a vector such that vecp. Vecr=|vecr|, |vecr-vecp|=2sqrt2 and the angle between vecp xx vecq and vecr is (pi)/(6) , then the value of |(vecpxxvecq)xx vecr| is equal to

Two vectors vecA and vecB inclined at an angle theta have a resultant vecR which makes an angle alpha with vecA and angle beta with vecB . Let the magnitudes of the vectors vecA, vecB and vecR be represented by A, B and R respectively. Which of the following relations is not correct ?

Vector vecR is the resultant of the vetors vecA and vecB . Ratio of maximum value of |vecR| to the minimum value of |vecR| is 3/1 . The (|vecA|)/(|vecB|) may be equal to-

Let veca=-hati-hatk,vecb =-hati + hatj and vecc = i + 2hatj + 3hatk be three given vectors. If vecr is a vector such that vecr xx vecb = vecc xx vecd and vecr.veca =0 then find the value of vecr .vecb .

A vector vecr is equally inclined with the vectors veca=cos thetahati+sin theta hatj, vecb=-sin theta hati+cos theta hatj and vecc=hatk , then the angle between vecr and veca is

NCERT EXEMPLAR-VECTOR ALGEBRA-Vector Algebra
  1. If vec aa n d vec b are position vectors of Aa n dB respectively, f...

    Text Solution

    |

  2. Using vectors, find the value of k, such that the points (k,-10, 3), (...

    Text Solution

    |

  3. A vector vecr is inclined at equal angles to the three axes. If the ma...

    Text Solution

    |

  4. If a vector vcer has magnitude 14 and direction ratios 2, 3 and -6. Th...

    Text Solution

    |

  5. Find a vector of magnitude 6, which is perpendicular to both the vecto...

    Text Solution

    |

  6. Find the angle between the vectors 2hati-hatj+hatkand3hati+4hatj-hatk.

    Text Solution

    |

  7. If veca+vecb+vecc=0, then show that vecaxxvecbxxvecc=veccxxveca. Inter...

    Text Solution

    |

  8. Find the sine of the angle between the vectors veca=3hati+hatj+2hatkan...

    Text Solution

    |

  9. If A, B, C and D are the points with position vectors hati-hatj+hatk,2...

    Text Solution

    |

  10. Using vectors, find the area of the DeltaABC with vertices A(1, 2, 3),...

    Text Solution

    |

  11. Using vectors, prove that the parallelogram on the same base and betwe...

    Text Solution

    |

  12. (Cosine Formulae) if a ,b ,c are the lengths of the sides opposite res...

    Text Solution

    |

  13. If veca,vecbandvecc determine the vertices of a triangle, show that (1...

    Text Solution

    |

  14. Show that area of the parallelogram whose diagonals are given by veca ...

    Text Solution

    |

  15. If veca=hati+hatj+hatk and vecb=hatj-hatk find a vector vecc such that...

    Text Solution

    |

  16. The vector in the direction of the vector hati-2hatj+2hatk that has ma...

    Text Solution

    |

  17. The position vector of the point which divides the join of points 2vec...

    Text Solution

    |

  18. The vector having initial and terminal points as (2, 5, 0) and (-3,7,4...

    Text Solution

    |

  19. The angle between two vectros vecaandvecb with magnitudes sqrt3 and 4,...

    Text Solution

    |

  20. Find the value of lamda such that the vectors veca=2hati+lamdahatj+hat...

    Text Solution

    |