Home
Class 11
MATHS
If cosbeta is the geometric mean between...

If `cosbeta` is the geometric mean between `sinalphaa n dcosalpha,` where `0ltalpha,betaltpi/ 2,`then`cos2beta` is equal to

Promotional Banner

Topper's Solved these Questions

  • STRAIGHT LINES

    CENGAGE PUBLICATION|Exercise All Questions|486 Videos

Similar Questions

Explore conceptually related problems

Find the geometric mean between 2a and 8a^3

Insert : n geometric means between a and b.

If cos beta is the geometric mean of sin alpha and cos alpha, then show that cos 2 beta= -2 cos^(2) ((pi)/(4)+alpha)

The expression cos^2(alpha+beta)+cos^2(alpha-beta)-cos2alpha.cos2beta, is

If sin^4alpha+cos^4beta+2=4sinalphacosbeta,0lt=alpha,betalt=pi/2 then find the value of (sinalpha+cosbeta)dot

If tanalpha is equal to the integral solution of the inequality 4x^2-16 x+15<0 and cosbeta is equal to the slope of the bisector of the first quadrant, then sin(alpha+beta)sin(alpha-beta) is equal to (a) 3/5 (b) 3/5 (c) 2/(sqrt(5)) (d) 4/5

The geometric mean of number 7, 7^2, 7^3,…..,7^n is

If cos alpha = 12/13, cos beta = 3/5 "and" cos gamma = 63/65"where" 0 ltalpha,beta,gammaltpi/2 "then the value of" cos(alpha + beta + gamma) "is"

The side of a triangle inscribed in a given circle subtends angles alpha,beta and gamma at the centre. The minimum value of the arithmetic mean of cos(alpha+pi/2),cos(beta+pi/2) , and cos(gamma+pi/2) is equal to ____

The geometric mean of the first n terms of the G.P. a,ar,ar^2 ,….is

CENGAGE PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
  1. If log(10)sin x + log(10)cos x=-1 and log(10)(sin x + cos x)=((log(10)...

    Text Solution

    |

  2. If tan(alpha-beta)=(sin2beta,)/(3-cos2beta) then (a)tanalpha=2tanbet...

    Text Solution

    |

  3. If cosbeta is the geometric mean between sinalphaa n dcosalpha, where ...

    Text Solution

    |

  4. In a triangle A B C , if A-B=120^0a n dsin(A/2)sin(B/2)sin(C/2)=1/(32...

    Text Solution

    |

  5. In a Delta PQR,angleR=pi/2. If tan(P/2) and tan (Q/2) are the roots of...

    Text Solution

    |

  6. If (tanx)/2=(tany)/3=(tanz)/5,x+y+z=pi and tan^2x+tan^2y+tan^2z is

    Text Solution

    |

  7. In A B C , if sin^3theta=sin(A-theta)sin(B-theta)sin(C-theta) , then ...

    Text Solution

    |

  8. If sin^(-1)a+sin^(-1)b+sin^(-1)c=pi, then the value of asqrt((1-a^2))+...

    Text Solution

    |

  9. Find the sum of the series cos e ctheta+cos e c2theta+cos e c4theta+ t...

    Text Solution

    |

  10. If tan6theta=p/q , find the value of 1/2(pcosec2theta-qsec2theta)

    Text Solution

    |

  11. If 0ltalphaltpi/2 and sinalpha+cosalpha+tanalpha+cotalpha+secalpha+cos...

    Text Solution

    |

  12. Prove that 1+cot theta <= cot (theta/2) for 0 &lt; theta &lt; pi. Find...

    Text Solution

    |

  13. Let A,B,C, be three angles such that A=pi/4 and tanB ,tanC=pdot Find a...

    Text Solution

    |

  14. Eliminate x from equations sin(a+x)=2b and sin(a-x)=2c.

    Text Solution

    |

  15. If t a nbeta=(nsinalphacosalpha)/(1-nsin^2alpha) , show that tan(alph...

    Text Solution

    |

  16. show that (sinx)/(cos3x)+(sin3x)/(cos9x)+(sin9x)/(cos27x)=1/2(tan27x-t...

    Text Solution

    |

  17. If theta=3alphaand sintheta=a/(sqrt(a^2+b^2)), the value of the expres...

    Text Solution

    |

  18. The value of tan6^0tan42^0tan66^0tan78^0 is (a)1 (b) 1/2 (c) 1/...

    Text Solution

    |

  19. In triangle A B C , if angle is 90^0 and the area of triangle is 30 sq...

    Text Solution

    |

  20. If sqrt(2)cos A=cos B+cos^3B ,a n dsqrt(2)sinA=sinB-sin^3B then sin(A...

    Text Solution

    |