Home
Class 11
MATHS
sec 72 ^(@) - sec 36^(@) = 2....

`sec 72 ^(@) - sec 36^(@) = 2.`

Promotional Banner

Topper's Solved these Questions

  • COMPOUND AND MULTIPLE ANGLES

    ICSE|Exercise CHEPTER TEST |23 Videos

  • COMPOUND AND MULTIPLE ANGLES

    ICSE|Exercise EXERCISE 5 (C ) |30 Videos

  • COMPLEX NUMBERS

    ICSE|Exercise Chapter Test|25 Videos

  • CONIC SECTIONS

    ICSE|Exercise Multiple Choice Questions |33 Videos

Similar Questions

Explore conceptually related problems

The value of sec 40^(@)+sec 80^(@)+sec 160^(@) will be

tan 2 A = (sec 2 A +1 ) sqrt ( (sec ^(2) A -1)) , A belongs to I or IV Quad.

Evaluate : 3(sin 72^(@))/(cos 18^(@))-(sec 32^(@))/(cosec 58^(@))

Prove that : (cosec A - sin A) (sec A - cos A) sec^(2) A = tan A

If m = a sec A + b tan A and n = a tan A + b sec A, then prove that : m^(2) - n^(2) = a^(2) - b^(2)

Evaluate: sec^(2)18^(@)-cosec^(2)72^(@)

Prove that: sec(45^(@)+A)sec(45^(@)-A)=2sec2A

Prove the following identities : (sec A)/ (sec A + 1) + (sec A)/ (sec A - 1) = 2 cosec^(2) A

Show that the coordinates of the orthocentre of DeltaABC is : ((x_1 a sec A + x_2 b sec B + x_3 c sec C)/(a sec A + b sec B + c sec A)), (y_1 a sec A + y_2 b sec B + y_3 c sec C)/(a sec A + b sec B + c sec C))

IF sec theta sin (36^(@) + theta) =1 . Find the value of theta so that theta and 36^(@) + theta are acute angles.

ICSE-COMPOUND AND MULTIPLE ANGLES -EXERCISE 5 (D)
  1. cos ^(2) 36^(@) + sin ^(2) 18^(@) = (3)/(4).

    Text Solution

    |

  2. 3 cos 72 ^(@) -4 sin ^(3) 18^(@) = cos 36 ^(@).

    Text Solution

    |

  3. cos ^(2) 48^(@) - sin ^(2) 12 ^(@) = (sqrt5+1)/(8).

    Text Solution

    |

  4. Prove that sin "" (1)/(10) pi cos ""(1)/(5) pi = (1)/(4).

    Text Solution

    |

  5. sec 72 ^(@) - sec 36^(@) = 2.

    Text Solution

    |

  6. sin ^(2) 24 ^(@) - sin ^(2) 6^(@) = (sqrt5 -1)/(8).

    Text Solution

    |

  7. sin 12 ^(@) sin 48^(@) sin 54 ^(@) = (1)/(8).

    Text Solution

    |

  8. Prove that 4 cos 6^(@) cos 42 ^(@) cos 66^(@) cos 78^(@) = (1)/(4).

    Text Solution

    |

  9. sin "" (pi)/(5) sin "" (2pi)/(5) sin ""(4pi)/(5) sin""(3pi)/(5) = (5)/...

    Text Solution

    |

  10. Prove that cos "" (2pi)/(15) cos "" (4pi)/(15) cos "" (8pi)/(15) cos "...

    Text Solution

    |

  11. cos ^(2) ""(pi)/(10) + cos ^(2) ""(2pi)/(5) + cos^(2) ""(3pi)/(5) + co...

    Text Solution

    |

  12. tan 6 ^(@) tan 42 ^(@) tan 66 ^(@) tan 78^(@) =1

    Text Solution

    |

  13. cos alpha cos 2 alpha cos 4 alpha cos 8 alpha = (1)/(16), if alpha =...

    Text Solution

    |

  14. cos 12 ^(@) cos 24 ^(@) cos 36 ^(@) cos 48^(@) cos 72^(@) cos 84^(@) =...

    Text Solution

    |

  15. If theta = (pi)/(2 ^(n) +1) prove that 2 ^(n) cos theta cos 2 theta c...

    Text Solution

    |

  16. If tan "" (x-y)/( 2 ), tan z, tan "" (x + y)/( 2) are in G.P. then sho...

    Text Solution

    |

  17. If sin theta is G.M. of sin phi and cos phi, then prove that cos 2 th...

    Text Solution

    |

  18. If m tan (theta - 30^(@))= n tan (theta + 120^(@)), show that cos 2 th...

    Text Solution

    |

  19. If sin alpha = lamda sin (theta - alpha ) then prove that tan (alpha...

    Text Solution

    |

  20. If tan ""(alpha )/(2) = sqrt ({(1 -e)/( 1 +e)}) tan ""(beta)/(2), Prov...

    Text Solution

    |