Home
Class 11
MATHS
AB is a vertical pole with B at the grou...

AB is a vertical pole with B at the ground level and A at the top. A man finds that the angle of elevation of the point A from a certain point C on the ground is `60^@`. He moves away from the pole along the line BC to a point D such that CD =7m. From D, the angle of elevation of the point A is `45^@`. Then the length of the pole is:

A

`(7 sqrt3)/2 1/(sqrt3+1) m`

B

`(7 sqrt3)/2 1/(sqrt3-1) m`

C

`(7 sqrt3)/2 (sqrt3+1) m`

D

`(7 sqrt3)/2 (sqrt3-1) m`.

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • TRIGNOMETRY

    MODERN PUBLICATION|Exercise EXERCISE|730 Videos

  • STRAIGHT LINES

    MODERN PUBLICATION|Exercise EXERCISE|304 Videos

Similar Questions

Explore conceptually related problems

The angle of elevation of the top of a tower from a point O, on the ground, which is 600 m away from the foot of the tower, is 45^@ . Obtain the height of the tower.

The angle of elevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower, is 30^@ . Find the height of the tower.

The angle of elevation of the top of a hill from a point is alpha . After walking b metres towards the top up a slope inclined at an angle beta to the horizontal,the angle of elevation of the top becomes gamma .Then the height of the hill is :

A person standing on the bank of a river observes that the angle of elevation of the top of a tree standing on theopposite bank is 60^@ . When he moves 40 m away from the bank, he finds the angle of elevation to be 30^@ . Find the height of the tree and the width of the river.

A pole 5 m high is fixed on the top of a tower. The angle of elevation of the top of the pole observed from a point 'A' on the ground is 60^@ and the angle of depression of the point ‘A’ from the top of the tower is 45^@ . Find the height of the tower

The angle of elevation of the top of a tower from a point A on the ground is 30^@ . On moving a distance of 20 metres towards the foot of the tower to a point B, the angle of elevation increases to 60^@ . Find the height of the tower and distance of the tower from the point A.

A tower stands vertically on the ground. Front a point on the ground. which is 15 m away from the foot of the tower, the angle of elevation of the top of the tower is found to be 60^@ . Find the height of the tower.

A statue 1.6 m tall stands on the top of a pedestal. From a point on the ground, the angle of elevation of the top of the statue is 60^@ and from the same point the angle of elevation of the top of the pedestal is 45^@ . Find the height of the pedestal.

The angle of elevation of the top Q of a vertical tower PQ from a point X on the ground is 60^@ . At a point Y, 40 m vertically above X, the angle of elevation is 45^@ . Find the height of the tower PQ and the distance XQ.

From a point P on the ground the angle of elevation of the top of a 10 m tall building is 30^@ . A flag is hoisted at the top of the building and the angle of elevation of the top of the flagstaff from P is 45^@ . Find the length of the flagstaff.

MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. If p and q are positive real numbers such that p^2+ q^2=1, then the m...

    Text Solution

    |

  2. If sin^-1(x/5) + cosec^-1(5/4)= pi/2, then a value of x is

    Text Solution

    |

  3. AB is a vertical pole with B at the ground level and A at the top. A m...

    Text Solution

    |

  4. For 0 lt theta lt pi/2 , the solution (s) of sum(m=1)^6cos e c(theta+(...

    Text Solution

    |

  5. If (sin^(4)x)/(2)+(cos^(4)x)/(3)=1/5, then

    Text Solution

    |

  6. Let A and B denote the statements A : cos alpha + cos beta + cos gam...

    Text Solution

    |

  7. For a regular polygon, let r and R be the radii of the inscribed and t...

    Text Solution

    |

  8. If the angles A, B and C of a triangle are in an arithmetic progressio...

    Text Solution

    |

  9. Let ABC be a triangle such that angle ABC =pi/6. If a, b and c denote ...

    Text Solution

    |

  10. Let cos(alpha+beta)""=4/5 and let sin (alpha+beta)""=5/(13) where 0lt=...

    Text Solution

    |

  11. If A=sin^(2)x+cos^(4)x, then for all real x

    Text Solution

    |

  12. The possible values of theta in (0,pi) such that sin (theta)+sin(4 th...

    Text Solution

    |

  13. Prove that 3/4 le cos^2 theta +sin^4 thetale1. Hence deduce that 3/4 l...

    Text Solution

    |

  14. Prove that : (2 cos 2^n theta +1)/(2cos theta +1)= (2cos theta-1)(2cos...

    Text Solution

    |

  15. Prove that tan alpha+2tan 2 alpha+4 tan 4 alpha+ 8 cos 8 alpha=cot a...

    Text Solution

    |

  16. Solve: 2 (cos x + cos 2x) + sin 2x (1 + 2 cos (x))=2 sinx,-pi le x le ...

    Text Solution

    |

  17. Find the values of x in (-pi, pi), which satisfy the equation : 8^(1+|...

    Text Solution

    |

  18. If p tan theta = tan p theta, then show that : (sin^2 p theta)/(sin^2 ...

    Text Solution

    |

  19. If a+b+c=0, then what is the value of a^2/(bc)+b^2/(ca)+c^2/(ab)

    Text Solution

    |

  20. Given the product p of sines of the angles of a triangle and the produ...

    Text Solution

    |