Home
Class 12
MATHS
if theta int (0,2pi) and 2sin^(2)theta-5...

if `theta int (0,2pi)` and `2sin^(2)theta-5sintheta+2 gt 0`, then the range of `theta` is

A

`(0,pi/6) cup ((5pi)/6, 2pi)`

B

`(0,pi/6) cup (pi,2pi)`

C

`(0,pi/6) cap (pi,2pi)`

D

`phi`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE ENGLISH|Exercise Section-C (Objective Type Questions More than one options are correct )|45 Videos
  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE ENGLISH|Exercise Section D (Linked Comprehension Type Questions)|27 Videos
  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE ENGLISH|Exercise Assignment Section-B (Objective Type Questions (One option is correct))|1 Videos
  • THREE DIMENSIONAL GEOMETRY

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT SECTION - J|10 Videos
  • VECTOR ALGEBRA

    AAKASH INSTITUTE ENGLISH|Exercise SECTION-J (Aakash Challengers Questions)|5 Videos

Similar Questions

Explore conceptually related problems

If theta in (0, 2pi) and 2sin^2theta - 5sintheta + 2 > 0 , then the range of theta is

If 3tan^(2)theta-2sintheta=0 , then general value of theta is:

The set of values of theta satisfying the inequatioin 2sin^(2)theta-5sintheta+2 gt 0, where o lt theta lt 2pi , is

int_0^(pi//2)(theta/sintheta)^2d theta=

If 0 leq theta leq pi and sin(theta/2)=sqrt(1+sintheta)-sqrt(1-sintheta) , then the possible value of tan theta is (a) 4/3 (b) 0 (c) -3/4 (d) -4/3

If cos 3theta+sin3theta+(2sin2theta-3)(sin theta-cos theta)gt0 , then theta lies in

If f (theta) = [[cos^(2) theta , cos theta sin theta,-sin theta],[cos theta sin theta , sin^(2) theta , cos theta ],[sin theta ,-cos theta , 0]] ,then f ( pi / 7) is

If 6sin^(2)theta - sin theta = 1 and 0 le theta le pi , what is the value of sin theta ?

To find the sum sin^(2) ""(2pi)/(7) + sin^(2)""(4pi)/(7) +sin^(2)""(8pi)/(7) , we follow the following method. Put 7theta = 2npi , where n is any integer. Then " " sin 4 theta = sin( 2npi - 3theta) = - sin 3theta This means that sin theta takes the values 0, pm sin (2pi//7), pmsin(2pi//7), pm sin(4pi//7), and pm sin (8pi//7) . From Eq. (i), we now get " " 2 sin 2 theta cos 2theta = 4 sin^(3) theta - 3 sin theta or 4 sin theta cos theta (1-2 sin^(2) theta)= sin theta ( 4sin ^(2) theta -3) Rejecting the value sin theta =0 , we get " " 4 cos theta (1-2 sin^(2) theta ) = 4 sin ^(2) theta - 3 or 16 cos^(2) theta (1-2 sin^(2) theta)^(2) = ( 4sin ^(2) theta -3)^(2) or 16(1-sin^(2) theta) (1-4 sin^(2) theta + 4 sin ^(4) theta) " " = 16 sin ^(4) theta - 24 sin ^(2) theta +9 or " " 64 sin^(6) theta - 112 sin^(4) theta - 56 sin^(2) theta -7 =0 This is cubic in sin^(2) theta with the roots sin^(2)( 2pi//7), sin^(2) (4pi//7), and sin^(2)(8pi//7) . The sum of these roots is " " sin^(2)""(2pi)/(7) + sin^(2)""(4pi)/(7) + sin ^(2)""(8pi)/(7) = (112)/(64) = (7)/(4) . The value of (tan^(2)""(pi)/(7) + tan^(2)""(2pi)/(7) + tan^(2)""(3pi)/(7))/(cot^(2)""(pi)/(7) + cot^(2)""(2pi)/(7) + cot^(2)""(3pi)/(7)) is

To find the sum sin^(2) ""(2pi)/(7) + sin^(2)""(4pi)/(7) +sin^(2)""(8pi)/(7) , we follow the following method. Put 7theta = 2npi , where n is any integer. Then " " sin 4 theta = sin( 2npi - 3theta) = - sin 3theta This means that sin theta takes the values 0, pm sin (2pi//7), pmsin(2pi//7), pm sin(4pi//7), and pm sin (8pi//7) . From Eq. (i), we now get " " 2 sin 2 theta cos 2theta = 4 sin^(3) theta - 3 sin theta or 4 sin theta cos theta (1-2 sin^(2) theta)= sin theta ( 4sin ^(2) theta -3) Rejecting the value sin theta =0 , we get " " 4 cos theta (1-2 sin^(2) theta ) = 4 sin ^(2) theta - 3 or 16 cos^(2) theta (1-2 sin^(2) theta)^(2) = ( 4sin ^(2) theta -3)^(2) or 16(1-sin^(2) theta) (1-4 sin^(2) theta + 4 sin ^(4) theta) " " = 16 sin ^(4) theta - 24 sin ^(2) theta +9 or " " 64 sin^(6) theta - 112 sin^(4) theta - 56 sin^(2) theta -7 =0 This is cubic in sin^(2) theta with the roots sin^(2)( 2pi//7), sin^(2) (4pi//7), and sin^(2)(8pi//7) . The sum of these roots is " " sin^(2)""(2pi)/(7) + sin^(2)""(4pi)/(7) + sin ^(2)""(8pi)/(7) = (112)/(64) = (7)/(4) . The value of (tan^(2)""(pi)/(7) + tan^(2)""(2pi)/(7) + tan^(2)""(3pi)/(7))xx (cot^(2)""(pi)/(7) + cot^(2)""(2pi)/(7) + cot^(2)""(3pi)/(7)) is

AAKASH INSTITUTE ENGLISH-TRIGNOMETRIC FUNCTIONS -Section-B (Objective Type Questions One option is correct)
  1. Solve sin^(4)x=1+tan^(8)x.

    Text Solution

    |

  2. If theta in (0, 2pi) and 2sin^2theta - 5sintheta + 2 > 0, then the ran...

    Text Solution

    |

  3. if theta int (0,2pi) and 2sin^(2)theta-5sintheta+2 gt 0, then the rang...

    Text Solution

    |

  4. The general solution of the equation tan2theta tan3theta=1 is

    Text Solution

    |

  5. If m, n in N( n> m), then number of solutions of the equation n|sin...

    Text Solution

    |

  6. If sinA = sinBandcosA=cosA=cosB, then which one of the following is c...

    Text Solution

    |

  7. The number of values of x int [-2pi, 2pi] satisfying tanx + cotx = 2" ...

    Text Solution

    |

  8. The solution set of the equation tanax = tanbx

    Text Solution

    |

  9. The general solution of the equation tanx/ (tan2x) + (tan2x)/tanx +2 =...

    Text Solution

    |

  10. The solution of the equation cos^2theta-2costheta=4sintheta-sin2theta ...

    Text Solution

    |

  11. The general solution of sin^2 theta sec theta +sqrt3 tan theta=0 is (n...

    Text Solution

    |

  12. If sinx+cosx=sqrt(y+1/y), y gt 0, x in[0,pi], then find the least valu...

    Text Solution

    |

  13. Find the number of solution(s) of the equation cos (pi sqrt(x)) cos ...

    Text Solution

    |

  14. The number of solutions of sum(r=1)^6 cos(rx)=6 in

    Text Solution

    |

  15. The number of values of x for which sin2x + cos4x = 2 is

    Text Solution

    |

  16. If the equation cosx + 3cos(2Kx) = 4 has exactly one solution, then

    Text Solution

    |

  17. The solution of the inequality log(1//2) sinx gt log(1//2) cosx is

    Text Solution

    |

  18. The values of k for which the equation sin^4 x+cos^4 x+sin2x+k=0 posse...

    Text Solution

    |

  19. If 4 sin^(4) x+ cos^(4) x=1, then x is equal to (n in Z)

    Text Solution

    |

  20. Find all values of theta lying between 0 and 2 pi , satisying the e...

    Text Solution

    |