Home
Class 14
MATHS
If cos^(4)alpha - sin^(4)alpha = 2/3, th...

If `cos^(4)alpha - sin^(4)alpha = 2/3`, then the value of `2 cos^(2)theta` is:

A

`5/3`

B

`4/3`

C

`2/3`

D

`3/2`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • ELEMENTARY TRIGONOMETRIC IDENTITIES

    LUCENT PUBLICATION|Exercise EXERCISE 11B|37 Videos

  • ELEMENTARY TRIGONOMETRIC IDENTITIES

    LUCENT PUBLICATION|Exercise EXERCISE 11B|37 Videos

  • CONGRUENCE AND SIMILAR TRIANGLES

    LUCENT PUBLICATION|Exercise EXERCISE-5B|8 Videos

  • GRAPHICAL SOLUTION OF LINEAR EQUATION

    LUCENT PUBLICATION|Exercise EXERCISE-3B|8 Videos

Similar Questions

Explore conceptually related problems

If sin^(2)alpha+ sin alpha=1 , then the value of cos^(4) alpha+ cos^(2) alpha is ________

If cos^(2)alpha+ cos alpha=1 , then find the value of 4 sin^(2)alpha+4 sin^(4) alpha+2 .

If (2 sin alpha)/(1 + cos alpha + sin alpha) = 3/4 , then the value of (1 + cos alpha + sinalpha)/(1 + sin alpha) is equal to

If (cos^(4)alpha)/(cos^(2)beta)+(sin^(4)alpha)/(sin^(2)beta)=1 then the value of (cos^(4)beta)/(cos^(2)alpha)+(sin^(4)beta)/(sin^(2)alpha) is

If cos (theta - alpha) = a, cos (theta - beta) = b , then the value of sin^(2) (alpha - beta) + 2ab cos (alpha - beta) is

If 32tan^(3)theta=2cos^(2)alpha-3cos alpha and 3cos2 theta=1 then the general value of alpha is

If cos(theta-alpha)=a and cos(theta-beta)=b then the value of sin^(2)(alpha-beta)+2ab cos(alpha-beta)

32tan^(8)theta=2cos^(2)alpha-3cos alpha and 3cos2 theta=1 then the general value of alpha is

If cos alpha + cos beta = 0 = sin alpha + sin beta, then value of cos 2 alpha + cos 2 beta is

LUCENT PUBLICATION-ELEMENTARY TRIGONOMETRIC IDENTITIES -EXERCISE 11A
  1. The identity (1+ tan theta - sec theta)(1+ cot theta - "cosec"theta) n...

    Text Solution

    |

  2. Which is equal to sectheta."cosec"theta ?

    Text Solution

    |

  3. The value of tan^(4)A + tan^(2)A in terms of secA is

    Text Solution

    |

  4. Find minimum value of sin^(2)theta+cosec^(2)theta+cos^(2)theta+sec^(...

    Text Solution

    |

  5. If cos^(2)alpha+cos^(2)beta=2, then the value of tan^(3)alpha+sin^(...

    Text Solution

    |

  6. If A = tan 11^(@) tan 29^(@), B = 2cot 61^(@) cot 79^(@), then which ...

    Text Solution

    |

  7. The simplified value of (SecA-cosA)^(2)+("cosec" A-sinA)^(2)-(cotA-t...

    Text Solution

    |

  8. The value of sin^2(1^@)+sin^2(5^@)+sin^2(9^@)+..........+sin^2(89^@) i...

    Text Solution

    |

  9. The numerical value of cot 18^(@) (cot 72^(@) cos^(2) 22^(@) + (1)/...

    Text Solution

    |

  10. If sinalphasec(30^(@)+alpha)=1(0^(@)ltalphalt60^(@)), then find the va...

    Text Solution

    |

  11. If cos^(4)alpha - sin^(4)alpha = 2/3, then the value of 2 cos^(2)theta...

    Text Solution

    |

  12. If theta be a positive acute angle satisfying cos^(2)theta+cos^(4)...

    Text Solution

    |

  13. If theta is an acute angle and tan theta + cot theta=2, then the value...

    Text Solution

    |

  14. (sin^(2)1^(@) + sin^(2)3^(@) + sin^(2)5^(@) +sin^(2)7^(@) + ….. + sin^...

    Text Solution

    |

  15. If 2cos theta - sin theta = 1/sqrt(2), (0^(@) lt theta lt 90^(@)) then...

    Text Solution

    |

  16. If (sin theta + cos theta)/(sin theta - cos theta)=3, then the value ...

    Text Solution

    |

  17. If sec^(2)theta+tan^(2)theta=7 , then the value of theta

    Text Solution

    |

  18. (secx.secy + tanx.tany)^(2)-(secx.tany + tanx.secy)^(2) in its simples...

    Text Solution

    |

  19. If (cos^(2) theta)/(cot^(2) theta - cos^(2) theta) = 3 and 0^(@) lt th...

    Text Solution

    |

  20. If sintheta - cos theta = 7/13 and 0 lt theta lt 90^(@),then the value...

    Text Solution

    |