Home
Class 11
MATHS
Prove that cos 2a=2sin^(2)beta+4cos (alp...

Prove that `cos 2a=2sin^(2)beta+4cos (alpha+beta)sin alpha sin beta+cos2(alpha+beta)`

Promotional Banner

Topper's Solved these Questions

  • BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION

    ALLEN|Exercise EXERCISE (JA)|16 Videos

  • BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION

    ALLEN|Exercise EXERCISE (JM)|8 Videos

  • BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION

    ALLEN|Exercise EXERCISE (O-1)|43 Videos

  • BASIC MATHS LOGARITHIM TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION

    ALLEN|Exercise ILLUSTRATIONS|39 Videos

  • INVERSE TRIGONOMETRIC FUNCTIONS

    ALLEN|Exercise All Questions|1 Videos

Similar Questions

Explore conceptually related problems

Prove that 2 sin^2 beta + 4 cos(alpha + beta) sin alpha sin beta + cos 2(alpha + beta) = cos 2alpha

Simplify 2sin^2beta+4cos(alpha+beta)sinalphasinbeta+cos2(alpha+beta)

Prove that: cos2alpha\ cos2beta+sin^2(alpha-beta)-sin^2(alpha+beta)=cos2(alpha+beta) .

If y = sin ^(2) alpha + cos ^(2) (alpha + beta) + 2 sin alpha sin betacos(alpha+beta) then (d^(3)y)/(dalpha^(3))=?

Prove that : (cos alpha + cos beta)^2 + (sin alpha + sin beta)^2 = 4 cos^2 ((alpha-beta)/(2))

Show that cos ^2 alpha + cos^2 (alpha +Beta) - 2 cos alpha cos betacos (alpha+ beta) =sin^2 beta

If the sides of a right angled triangle are {cos 2 alpha + cos 2 beta + 2 cos (alpha+beta)} and {sin 2 alpha+sin 2 beta + 2 sin (alpha+beta)} then the length of the hypotneuse is

Prove that : cos^2alpha+cos^2(alpha+beta)-2cosalphacosbetacos(alpha+beta)=sin^2beta

If the eccentric angles of the extremities of a focal chord of an ellipse x^2/a^2 + y^2/b^2 = 1 are alpha and beta , then (A) e = (cos alpha + cos beta)/(cos (alpha + beta)) (B) e= (sin alpha + sin beta)/(sin(alpha + beta)) (C) cos((alpha-beta)/(2)) = e cos ((alpha + beta)/(2)) (D) tan alpha/2.tan beta/2 = (e-1)/(e+1)

By geometrical interpretation, prove that (i) sin(alpha+beta)=sin alpha cos beta+sinbeta cosalpha (ii) cos(alpha+beta)=cosalpha cosbeta -sin alpha sinbeta

ALLEN-BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION -EXERCISE (S-1)
  1. The set of real values of x for which (log(x)2)(log(x)2)(log(2)4x) ...

    Text Solution

    |

  2. about to only mathematics

    Text Solution

    |

  3. Prove that cos 2a=2sin^(2)beta+4cos (alpha+beta)sin alpha sin beta+cos...

    Text Solution

    |

  4. Prove that: s in^4pi/8+s in^4(3pi)/8+s in^4(5pi)/8+s in^4(7pi)/8=3/2

    Text Solution

    |

  5. If x=sin(theta+(7pi)/(12))+sin(theta+pi/(12))+sin(theta+(3pi)/(12))dot...

    Text Solution

    |

  6. If tan.(pi)/(24)=(sqrt(p)-sqrt(q))(sqrt(r )-s), then the value of p+q+...

    Text Solution

    |

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

    Text Solution

    |

  8. It cos(alpha+beta)=4/5,sin(alpha-beta)=5/(13)a n dalpha,beta lie betwe...

    Text Solution

    |

  9. If the value of the expression sin 25^@* sin 35^@* sin 85^@ can be exp...

    Text Solution

    |

  10. Prove that (4cos^2 9^0-3)(4cos^2 27^0-3)=tan9^0dot

    Text Solution

    |

  11. Prove that 4cos(2pi)/7dotcospi/7-1=2cos(2pi)/7dot

    Text Solution

    |

  12. Let P(k)=(1+cospi/(4k)) (1+cos((2k-1)pi)/(4k)) (1+cos((2k+1)pi)/(4k))...

    Text Solution

    |

  13. Evaluate (2cos4 0^(@)-cos2 0^(@))/(sin2 0^(@)

    Text Solution

    |

  14. Solve cos^6(pi/16)+cos^6((3pi)/16)+cos^6((5pi)/16)+cos^6((7pi)/16)

    Text Solution

    |

  15. Given that (1+tan1^@)(1+tan2^@)...........(1+tan45^@)= 2^n find n .

    Text Solution

    |

  16. Prove that from the equality (sin^(4)alpha)/a+(cos^(4)alpha)/b=1/(a+b)...

    Text Solution

    |

  17. If a leq 3 cos (theta+pi/3)+5cos theta+3 leq b, find a and b, where ...

    Text Solution

    |

  18. The value of (cotθ+cosecθ-1)/ (cotθ-cosecθ+1) is

    Text Solution

    |

  19. If x and y are real number such that x^2 +2xy-y^2=6, find the minimum...

    Text Solution

    |

  20. If A+B+C=pi, prove that tan^2A/2+tan^2B/2+tan^2C/2geq1.

    Text Solution

    |