Home
Class 11
MATHS
If (sin^4theta)/a+(cos^4theta)/b=1/(a+b)...

If `(sin^4theta)/a+(cos^4theta)/b=1/(a+b)` , prove that `(sin^8theta)/(a^3)+(cos^4theta)/(b^3)=1/((a+b)^3)` `(sin^(4n)theta)/(a^(2n-1))+(cos^(4n)theta)/(b^(2n-1))=1/((a+b)^(2n-1)),n in N`

Text Solution

Verified by Experts

Given,`(sin^4theta)/a+(cos^4theta)/b=1/(a+b)`
`=>(sin^4theta)/a+((1-sin^2theta)^2)/b=1/(a+b)`
`=>(bsin^4alpha+a(1+sin^4alpha−2sin^2alpha))=1/(a+b)`
`=>bsin^4alpha+a+asin^4alpha−2asin^2alpha=1/(a+b)`
`=>(a+b)sin^4alpha−2asin^2alpha=1/(a+b)−a`
`=>(a+b)sin^4alpha−2asin^2alpha=(1−ab−a^2)/(a+b)`
`=>sin^2alpha=a/(a+b),cos^2alpha=b/(a+b)`
...
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC EQUATIONS

    RD SHARMA|Exercise Solved Examples And Exercises|120 Videos
  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    RD SHARMA|Exercise Solved Examples And Exercises|149 Videos

Similar Questions

Explore conceptually related problems

If (sin^(4)theta)/(a)+(cos^(4)theta)/(b)=(1)/(a+b), then (sin^(8)theta)/(a^(3))+(cos^(8)theta)/(b^(3))=

if (cos^(2)theta)/(a)=(sin^(2)theta)/(b) then (cos^(4)theta)/(a)+(sin^(4)theta)/(b)=?

If sin((theta)/(2))=a,cos((theta)/(2))=b then (1+sin theta)/(3sin theta+4cos theta+5)=

Prove that sin theta cos^(3)theta - cos theta sin^(3) theta = (1)/(4) sin 4 theta .

(sin 3 theta)/(sin theta)-(cos 3 theta)/(cos theta)= A) sin 2 theta B) cos 4 theta C)1D)2

If sin(pi cos theta)=cos(pi sin theta) ,then prove that : theta=(1)/(2)sin^(-1)(3/4)

If sin theta+sin^(2)theta+sin^(3)theta=1, then prove that cos^(6)theta-4cos^(4)theta+8cos^(2)theta=4

If tan theta=(a)/(b), the n(sin theta)/(cos^(8)theta)+(cos theta)/(sin^(8)theta)=

Prove that: sin theta cos^(3)theta-cos theta sin^(3)theta=(1)/(4)sin4 theta

RD SHARMA-TRIGONOMETRIC FUNCTIONS-Solved Examples And Exercises
  1. If 2t a n^2alphat a n^2betat a n^2gamma+t a n^2alphat a n^2beta+t a ...

    Text Solution

    |

  2. If m^2 + m'^2 + 2mm' costheta = 1 and n^2+n'^2+2n n'costheta=1, (mn +...

    Text Solution

    |

  3. If (sin^4theta)/a+(cos^4theta)/b=1/(a+b) , prove that (sin^8theta)/...

    Text Solution

    |

  4. If (cos^4alpha)/(cos^2beta)+(sin^4alpha)/(sin^2beta)=1 prove that (i...

    Text Solution

    |

  5. If x is any non-zero real number, show that costheta' a n d ' sinthet...

    Text Solution

    |

  6. If A=cos^2theta+sin^4theta, prove that 3/4lt=Alt=1 for all values of...

    Text Solution

    |

  7. If tantheta+sectheta=e^x then costheta equals

    Text Solution

    |

  8. Prove that:sqrt((1-costheta)/(1+costheta))={cosectheta-cottheta,if 0 <...

    Text Solution

    |

  9. If sec theta=sqrt(2)a n d(3pi)/2<theta<2pi ,="" find="" the="" value="...

    Text Solution

    |

  10. Prove the following identities: sin^8theta-cos^8theta=(sin^2theta-cos^...

    Text Solution

    |

  11. Prove the following identities: cot^4theta+cot^2theta=cos e c^4theta-c...

    Text Solution

    |

  12. Prove the following identities: 2sec^2theta-sec^4theta-2cos e c^2theta...

    Text Solution

    |

  13. Prove the following identities: (sintheta+cos e ctheta)^2+(costheta+s...

    Text Solution

    |

  14. Prove the following identity: (1+cottheta-cos e ctheta)(1+t a ntheta+s...

    Text Solution

    |

  15. Prove the following identity: (t a ntheta+s e ctheta-1)/(t a ntheta-s ...

    Text Solution

    |

  16. If costheta+sintheta=sqrt(2)costheta, show that costheta-sintheta=sqrt...

    Text Solution

    |

  17. If acostheta+b sintheta=x and asintheta-bcostheta=y prove that a^2+...

    Text Solution

    |

  18. If tan theta +sin theta =m and tan theta -sin theta =n then prove m^2-...

    Text Solution

    |

  19. Prove the following identity: sec^4theta-sec^2theta=tan^4theta+tan^2th...

    Text Solution

    |

  20. Prove that sin^6theta+cos^6theta=1-3sin^2thetacos^2theta

    Text Solution

    |