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If tanโก๐œƒ =1โˆš5,write the value of(cosโก๐‘’โข๐‘2โข๐œƒโˆ’sec2โก๐œƒ)(cosโก๐‘’โข๐‘2โข๐œƒโˆ’sec2โก๐œƒ).

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Question

If `tan theta = 1/sqrt(5), "write the value of" (( cosec^2 theta - sec^2 theta))/(( cosec^2 theta - sec^2 theta))`.

Sum
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Solution

   ` (( cosec^2 theta - sec^2 theta))/((cosec^2 theta + sec^2 theta))`

  =` ((1+cot^2 theta) -( 1+ tan^2 theta))/((1+ cot^2 theta)+( 1+ tan^2 theta))`

    =`((1+ 1/ tan^2 theta)-(1+ tan^2 theta))/((1+ 1/ tan^2 theta)-(1+ tan^2 theta))`

     =`((1+ 1/ tan^2 theta-1- tan^2 theta))/((1+ 1/ tan^2 theta +1+ tan^2 theta))`

      =` ((1/ tan^2 theta - tan^2 theta ))/((1/ tan^2 theta + tan^2 theta +2))`

     =`((sqrt(5)/1)^2 - ( 1/sqrt(5))^2 )/((sqrt(5)/1)^2 + (1/sqrt(5))^2+2)`

    =`((5/1+1/5))/((5/1+1/5+2/1))`

    =`((24/5))/((36/5))`

    =`24/36`

     =`2/3`

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Chapter 13: Trigonometric identities - Exercises 3

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R.S. Aggarwal Mathematics [English] Class 10
Chapter 13 Trigonometric identities
Exercises 3 | Q 23

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