Math, asked by shreyamoscow, 1 year ago

Prove that tan theta/1-cot theta +cot theta/1-tan theta - 1 = sec theta * cosec theta

Answers

Answered by azizalasha
2

Answer:

Proved

Step-by-step explanation:

let theta = ∝

tan theta/1-cot theta +cot theta/1-tan theta - 1 = sec theta * cosec theta

tan ∝/1-cot ∝ +cot ∝/1-tan ∝ - 1 = sec ∝* cosec∝

LHS =  tan ∝/1-cot ∝ +cot ∝/1-tan ∝ - 1 = tan ∝/1-1/tan∝ +1/tan ∝/1-tan ∝ - 1

= tan² ∝/tan∝-1 +1/tan∝(1-tan ∝) - 1 = tan² ∝/tan∝-1 -1/tan∝(tan ∝-1) - 1

= tan³∝ - 1/tan∝(tan ∝-1)  - 1 = tan²∝ +tan∝ +1 / tan∝ - 1 = tan∝ + cot∝ + 1-1

=  tan∝ + cot∝ = sin∝/cos∝ + cos∝/sin∝ =  sin²∝ + cos²∝/sin∝ cos∝

= 1/sin∝ cos∝ = sec ∝* cosec∝ = RHS

Answered by Anonymous
0

GIVEN:-

 \sf  \frac{ \tan \theta}{1 -  cot\theta }  +  \frac{  \cot \theta}{ 1 -  \tan \theta}  = 1 +  \sec \theta \cosec  \theta

TO FIND:-

 \tt lhs = rhs

SOLUTION:-

 \tt lhs \ratio  -

 \sf  \frac{ \tan \theta}{1 -  cot\theta }  +  \frac{  \cot \theta}{ 1 -  \tan \theta}

 \tt  =  \frac{ \frac{ \sin \theta  }{ \cos\theta } }{1 -  \frac{\cos\theta}{\sin \theta}  }  +    \frac{\frac{\cos\theta}{\sin \theta}  }{1 - \frac{ \sin \theta  }{ \cos\theta }}

 \tt =   \frac{ \frac{ \sin \theta  }{ \cos\theta } }{ \frac{ \sin \theta- \cos\theta}{  \sin \theta}  }  +    \frac{\frac{\cos\theta}{\sin \theta}  }{ \frac{  \cos\theta  -  \sin \theta  }{ \cos\theta }}

 \tt  =  \frac{ \sin \theta   }{ \cos \theta  }  \times  \frac{ \sin \theta  }{(\sin \theta - \cos \theta )   }  +  \frac{\cos \theta }{\sin \theta}  \times \frac{  \cos  \theta  }{( \cos  \theta -   \sin \theta )   }

 \tt =  \frac{  { \sin}^{2}\theta}{ \cos \theta( \sin \theta -  \cos \theta)  }  -  \frac{ { \cos }^{2}  \theta }{ \sin \theta( \sin \theta -  \cos \theta )    }

 \tt  =  \frac{1}{( \sin \theta  -  \cos \theta) } [ \frac{ { \sin}^{2}  \theta }{ \cos \theta  }  -  \frac{ { \cos }^{2}  \theta}{ \sin \theta  } ]

 \tt  =  \frac{1}{( \sin \theta  -  \cos \theta) } [    \frac{ { \sin}^{3  } \theta -  { \cos }^{3} \theta  }{ \sin \theta \cos \theta  }  ]

 \tt  =  \frac{1}{( \sin \theta  -  \cos \theta) } [   \frac{( \sin \theta -  \cos \theta)( { \sin}^{2}  \theta +  { \cos }^{2}    \theta +  \sin \theta \cos \theta )}{ \sin \theta \cos \theta    }   ]

 \tt  = \frac{(1 +  \sin \theta \cos \theta)}{( \sin \theta \cos \theta)}  =  \frac{1}{ \sin \theta \cos \theta  }  +  \frac{( \sin \theta \cos \theta)   }{( \sin \theta \cos \theta)  }

 =  \sec \theta \cosec \theta + 1

 = rhs

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