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If un=sin^("n")theta+cos^ntheta, then pr...

If `u_n=sin^("n")theta+cos^ntheta,` then prove that `(u_5-u_7)/(u_3-u_5)=(u_3)/(u_1)` .

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`(u_5-u_(7))/(u_3-u_(5))=((sin^5theta +cos^5theta)-(sin^7theta+cos^7theta))/((sin^3theta +cos^3theta)-(sin^5theta+cos^5theta))`
`(sin^5theta(1-sin^2theta)+cos^5theta(1-cos^2theta))/(sin^3theta(1-sin^2theta)+cos^3theta(1-cos^2theta))`
`=(sin^2thetacos^2theta[sin^3theta+cos^3theta])/(sin^2thetacos^2theta[sintheta+costheta])=u_3/u_1`
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CENGAGE-TRIGONOMETRIC FUNCTIONS -SINGLE CORRECT ANSWER TYPE
  1. If un=sin^("n")theta+cos^ntheta, then prove that (u5-u7)/(u3-u5)=(u3)/...

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  2. The circular wire of diameter 10 cm is cut and placed along the circum...

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  3. sintheta/(1-cottheta)+costheta/(1-tantheta)= (a)theta (b)1 (c)costh...

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  9. If sintheta,tantheta,costheta are in G.P. then 4sin^2theta-3sin^4theta...

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  10. If tantheta-cottheta=aandsintheta+costheta=b(b^2-1)^2(a^2+4) is equal...

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  11. The least value of 18 sin^(2)theta+2 cosec^(2)theta-3 is

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  18. If the angle A of a triangle ABC is given by the equation 5 cos A + 3 ...

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  19. Which of the following is greatest ?

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  21. Which of the following is not correct ?

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