Home
Class 12
MATHS
If hata and hatb are unit vectors inclin...

If `hata and hatb` are unit vectors inclined at angle `theta` then `(1)/(2)|hata+hatb|` is

A

`"sin"(theta)/(2)`

B

`cos 2 theta`

C

`"cos"(theta)/(2)`

D

`cos2theta`

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • APPLICATIONS OF VECTOR ALGEBRA

    PREMIERS PUBLISHERS|Exercise PROBLEMS FOR PRACTICE (Answer the following questions)|21 Videos

  • APPLICATIONS OF VECTOR ALGEBRA

    PREMIERS PUBLISHERS|Exercise SOLUTION TO EXERCISE 6.10|25 Videos

  • APPLICATIONS OF MATRICES AND DETERMINANTS

    PREMIERS PUBLISHERS|Exercise PROBLEMS FOR PRACTICE (II. Answer the following)|15 Videos

  • COMPLEX NUMBERS

    PREMIERS PUBLISHERS|Exercise Problem for practice|45 Videos

Similar Questions

Explore conceptually related problems

If hat a and hat b are unit vectors inclined at an angle θ then prove that : tan (θ/2) =|hat a + hat b|/ |hat a − hatb|

If hata,hatb and hatc are three unit vectors inclined to each other at an angle theta . The maximum value of theta is

If veca and vecb are two unit vectors inclined at an angle pi//3 then { veca xx (vecb+veca xx vecb)} .vecb is equal to

If veca and vecb are two vectors and angle between them is theta , then

If vec aa n d vec b are two unit vectors incline at angle pi//3 , then { vec axx( vec b+ vec axx vec b)}dot vec b is equal to a. (-3)/4 b. 1/4 c. 3/4 d. 1/2

If vec a and vec b are two unit vectors and theta is the angle between them, then |vec a - vec b| is equal to ______________

Statement 1: If vec ua n d vec v are unit vectors inclined at an angle alphaa n d vec x is a unit vector bisecting the angle between them, then vec x=( vec u+ vec v)//(2sin(alpha//2)dot Statement 2: If "Delta"A B C is an isosceles triangle with A B=A C=1, then the vector representing the bisector of angel A is given by vec A D=( vec A B+ vec A C)//2.

If hata,hatb and hatc are three unit vectors satisfying hata-sqrt3hatb+hatc=hat0 then find the angle between hata and hatc .

Unit vectors veca and vecb ar perpendicular , and unit vector vecc is inclined at an angle theta to both veca and vecb . If alpha veca + beta vecb + gamma (veca xx vecb) then.

If hat a , hat b ,a n d hat c are three unit vectors, such that hat a+ hat b+ hat c is also a unit vector and theta_1,theta_2a n dtheta_3 are angles between the vectors hat a , hat b ; hat b , hat ca n d hat c , hat a respectively, then among theta_1,theta_2,a n dtheta_3dot a. all are acute angles b. all are right angles c. at least one is obtuse angle d. none of these

PREMIERS PUBLISHERS-APPLICATIONS OF VECTOR ALGEBRA-PROBLEMS FOR PRACTICE (Choose the correct answer)
  1. If veca+vecb+vecc =0, |veca|=3, |vecb|=5, |vecc|=7 then the angle betw...

    Text Solution

    |

  2. If hata and hatb are unit vectors inclined at angle theta then (1)/(2)...

    Text Solution

    |

  3. If veca, vecb, vecc are three mutually perpendicular unit vectors then...

    Text Solution

    |

  4. If |veca xx vecb|=veca-vecb then the angle between veca and vecb is :

    Text Solution

    |

  5. If [veca+vecb, vecb+vec c, vec c+veca]=8 then [veca, vecb, vec c] is

    Text Solution

    |

  6. If the area of the parallelogram having diagonals veca=3hati+hatj-2hat...

    Text Solution

    |

  7. If veca=2hati+hatj-hatk, vecb= -hati+2hatj+hatk, vecc=-hati+2hatj-hatk...

    Text Solution

    |

  8. The force vecF=2hati+2hatj-2hatk acting at the point hati-2hatj+hatk i...

    Text Solution

    |

  9. If |veca|=5|vecb|=4 and |veca+vecb|=1 then |veca-vecb|=?

    Text Solution

    |

  10. The projectionof hati-hatj on z axis:

    Text Solution

    |

  11. Given veca*vecc=4, veca*vecd=3, vecb*vecc=2, vecb*vecd=3. Then value o...

    Text Solution

    |

  12. The vector vec(AB)=3hati+2hatj+2hatk and vec(BC)= - hati-2hatk are adj...

    Text Solution

    |

  13. If the angle between the lines having direction ratios (alpha, 3,5) an...

    Text Solution

    |

  14. Let a, b, c be distinct non negative numbers. The vectors ahati+a hatj...

    Text Solution

    |

  15. hati *(hatj xx hatk) +hatj(hatk xx hati) +hatk (hati xx hatj) is :

    Text Solution

    |

  16. If veca is any vector then the value of Sigma (veca xx veci)^(2) is :

    Text Solution

    |

  17. If (1-p)hati+2(1+p)hatj+(3+p)hatk and 3hati+hatj are at right angle to...

    Text Solution

    |

  18. [veca, veca+vecb, veca+vecb+vecc] is :

    Text Solution

    |

  19. The sum of the projection of 2hati+hatj+2hatk on the coordinate axis i...

    Text Solution

    |

  20. If veca=hati-2hatj+hatk, vecb=hati+2hatj+3hatk, vec c=3hati+2hatj+hatk...

    Text Solution

    |