Home
Class 11
MATHS
Prove that 2 sin^2 beta + 4 cos(alpha +...

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

Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC EQUATION

    ALLEN|Exercise All Questions|86 Videos

Similar Questions

Explore conceptually related problems

2sin^(2)beta+4cos(alpha+beta)sin alpha sin beta+cos2(alpha+beta)=

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

Show that 2"sin"^(2)beta+4 cos(alpha+beta)"sin" alpha sin beta+cos2(alpha+beta)=cos 2alpha .

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

What is sin (alpha+beta) - 2 sin alpha cos beta + sin(alpha- beta) =

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

If cos alpha+cos beta=0=sin alpha+sin beta then cos2 alpha+cos2 beta=

sin ^ (2) alpha + cos ^ (2) (alpha + beta) + 2 sin alpha sin beta cos (alpha + beta) = (i) sin ^ (2) (alpha) (ii) sin ^ (2) (beta ) (iii) cos ^ (2) (alpha) (iv) cos ^ (2) (beta)

If cos alpha+cos beta=0=sin alpha+sin beta. Prove that cos2 alpha+cos2 beta=-2cos(alpha+beta)

ALLEN-TRIGONOMETRIC RATIOS AND IDENTITIES-All Questions
  1. One angle of a triangle is (4x)/3 grades and another is 3x degrees, wh...

    Text Solution

    |

  2. If cos(y-z)+cos(z-x)+cos(x-y)=-3/2, prove that cos x + cos y + cos z =...

    Text Solution

    |

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

    Text Solution

    |

  4. For all value of alpha,beta,gamma prove that ,cosalpha+cosbeta+cosgamm...

    Text Solution

    |

  5. If cos(alpha+beta)=4/5; sin(alpha-beta)=5/13 and alpha,beta lie betwee...

    Text Solution

    |

  6. sin^4(pi/16)+sin^4(3pi/16)+sin^4(5pi/16)+sin^4(7pi/16)=3/2

    Text Solution

    |

  7. If costheta=(cosalpha-e)/(1-e cosalpha),\ prove that tantheta/2=+-sqr...

    Text Solution

    |

  8. Prove that, cot 7 1/2 ^@ or tan 82 1/2 ^@ = (sqrt(3)+sqrt(2))(sqrt(2)+...

    Text Solution

    |

  9. Prove that : cosec theta + cosec 2 theta + cosec 2^2 theta +.............

    Text Solution

    |

  10. Find the maximum & minimum values of 27^(cos2x). 81^(s in2x)

    Text Solution

    |

  11. Find the smallest positive values of xa n dy satisfying x-y=pi/4a n dc...

    Text Solution

    |

  12. if m*tan(theta-30)=n*tan(theta+120), show that cos2theta=(m+n)/(2(m-n)...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  16. If (1+t a n1^0)dot(1+t a n2^0)dot(1+t a n3^0)(1+tan45^0)=2^n , then ' ...

    Text Solution

    |

  17. Prove that in an acute triangle ABC, the least values of Sigma secA an...

    Text Solution

    |

  18. If tan(alpha)= p/q where alpha=6 beta, alpha being an acute angle, pr...

    Text Solution

    |

  19. If tan(pi/4+)=tan^3(pi/4+x/2)dot Prove that (siny)/(sinx)=(3+sin^2x)/...

    Text Solution

    |

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

    Text Solution

    |