Home
Class 11
MATHS
If costheta=1/2(a+1/a)\ t h e n\ cos 3th...

If `costheta=1/2(a+1/a)\ t h e n\ cos 3theta` in term of `' a^(prime)=` a.`1/4(a^3 1/(a^3))` b. `4\ (a^3+1/(a^3))` c.`1/2(a^3(1/(a^3))` d. none

Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC EQUATION

    ALLEN|Exercise All Questions|86 Videos

Similar Questions

Explore conceptually related problems

If costheta=1/2(a+1/a), show that : cos3theta=1/2(a^3+1/a^3)

If cos theta=(1)/(2)(a+(1)/(a)) then show that cos3 theta=(1)/(2)(a^(3)+(1)/(a^(3)))

If cos theta=(1)/(2)(a+(1)/(a)),cos3 theta=lambda(a^(3)+(1)/(a^(3))), then lambda(a)-(1)/(4) (b) (1)/(4) (c) 1 (d) none of these

costheta.cos2theta.cos3theta=1/4

If sin theta = (1)/(2) and theta is acute, the (3 cos theta - 4 cos^(3) theta) is equal to (a)0 (b) (1)/(2) (c) (1)/(6) (d) -1

i) Prove that: (1-sin2A)/(1+sin2A) = tan^(2)(pi/4-A) ii) If costheta=1/2(x+1/x) , then prove that: cos2theta=1/2(x^(2)+1/x^(2)) and cos3theta=1/2(x^(3)+1/x^(3))

Let H_(n)=1+(1)/(2)+(1)/(3)+ . . . . .+(1)/(n) , then the sum to n terms of the series (1^(2))/(1^(3))+(1^(2))/(1^(3))+(2^(2))/(2^(3))+(1^(2)+2^(2)+3^(2))/(1^(3)+2^(3)+3^(3))+ . . . , is

Coefficient of the constant term in the expansion of E=(x^(2/3)+4x^(1/3)+4)^(5)((1)/(x^(1/3)-1)+(1)/(x^(2/3)+x^(1/3)+1))

ALLEN-TRIGONOMETRIC RATIOS AND IDENTITIES-All Questions
  1. If the expression 4sin5alphacos3alphacos2alpha s expressed as the ...

    Text Solution

    |

  2. find the value of the expression 3[sin^4(3pi/2-alpha)+sin^4(3pi+alph...

    Text Solution

    |

  3. If costheta=1/2(a+1/a)\ t h e n\ cos 3theta in term of ' a^(prime)= a...

    Text Solution

    |

  4. The product cot123^@*cot133^@*cot137^@*cot147^@, when simplified is e...

    Text Solution

    |

  5. If A+B+C=pi\ &sin(A+C/2)=ksinC/2, t h e ntanA/2tanB/2= a.(k-1)/(k+1) ...

    Text Solution

    |

  6. The value of the expression (1-4sin 10^0\ sin 70^0)/(2sin 10^0\ ) is-...

    Text Solution

    |

  7. Which of the following number (s) is/are rational ? a.sin 15^0 b....

    Text Solution

    |

  8. If alpha+beta+gamma=2pi,\ then- a.tanalpha/2+(tan\ beta)/2+tangamma...

    Text Solution

    |

  9. If A and C are two angles such that A+C=(3pi)/4 then (1+cotA)(1+cotC)=

    Text Solution

    |

  10. (log)(t1)(4sin9^0cos9^0)w h e r e\ t1=4sin 63^0cos 63^0\ e q u a l s ...

    Text Solution

    |

  11. l=((cot^2x.cos^2x)/(cot^2x-cos^2x))^2 and m=a^(log(sqrt(a))[2cos(y/2)]...

    Text Solution

    |

  12. If (a+b)tan(theta-varphi)=(a-b)tan(theta+varphi),\ t h e n(sin(2theta)...

    Text Solution

    |

  13. If theta is the internal angle of n sided regular polygon, then sinthe...

    Text Solution

    |

  14. Let m=t a n3\ a n d\ n=s e c6,\ then which of the following statement...

    Text Solution

    |

  15. "I f"pi<2theta<(3pi)/2,"t h e n"sqrt(2+sqrt(2+2cos4theta))

    Text Solution

    |

  16. (sin^3theta-cos^3theta)/(sintheta-costheta)-(costheta)/(sqrt(1+cot^2th...

    Text Solution

    |

  17. If sce A=17/8 and cosec B=5/4, then sec(A+B) can have the value equal ...

    Text Solution

    |

  18. Which os the following when simplified reduces to unity ? (1-2sin^2alp...

    Text Solution

    |

  19. It is known that sinbeta=4/5 and 0 < beta < pi then the value of (sqrt...

    Text Solution

    |

  20. In a triangle ABC, angle A is greater than angle B. If the measures of...

    Text Solution

    |