Math, asked by beharatanusri, 11 months ago

prove that cosA/1-tanA+sinA/1-cotA=sinA+cosA​

Answers

Answered by eena6992
0

Answer:

LHS

=cosA/(1-tanA)+sinA/(1-cotA)

=cos A/(1 - sin A/cos A) + sin A/(1 - cos A/sin A)

=cos²A/ (cos A - sin A) + sin²A / (sin A - cos A)

=cos²A/ (cos A - sin A) - sin²A / (cos A - sin A)

=(cos ² A - sin ² A) / (cos A - sin A)

=(cos A - sin A)(cos A + sin A) / (cos A - sin A)

=cos A + sin A i.e RHS

Answered by chaitragouda8296
0

To Prove :

 \frac{cos}{1 - tan}  +  \frac{sin}{1 - cot}  = sin \:  + cos

Solution :

LHS =

 =  \frac{cos}{1 - tan}  +  \frac{sin}{1 - cot}  \\  \\  =  \frac{cos}{1 -  \frac{sin}{cos} }  +  \frac{sin}{1 -  \frac{cos}{sin} }  \\  \\  =  \frac{cos}{ \frac{cos - sin}{cos} }  +  \frac{sin}{ \frac{sin - cos}{sin} }  \\  \\  = cos \times  \frac{cos}{cos - sin}  + sin \times  \frac{sin}{sin - cos}  \\  \\  =  \frac{ {cos}^{2} }{cos - sin}  +  \frac{ {sin}^{2} }{sin - cos}  \\  \\  =  \frac{ {cos}^{2} }{cos - sin}  +  \frac{ {sin}^{2} }{ - ( - sin + cos</em></strong><strong><em>)</em></strong><strong><em> </em></strong><strong><em>  </em></strong><strong><em>}</em></strong><strong><em>\\  \\  =  \frac{ {cos}^{2} }{</em></strong><strong><em>(</em></strong><strong><em>cos - </em></strong><strong><em>sin</em></strong><strong><em>)</em></strong><strong><em> </em></strong><strong><em>}  -  \frac{ {sin}^{2} }{</em></strong><strong><em>(</em></strong><strong><em>cos - s</em></strong><strong><em>in</em></strong><strong><em>)</em></strong><strong><em> </em></strong><strong><em> </em></strong><strong><em>}</em></strong><strong><em> \\  \\  =  \frac{ {cos}^{2}  -  {sin }^{2} }{cos - sin}  \\  \\ </em></strong><strong><em>Her</em></strong><strong><em>e</em></strong><strong><em> </em></strong><strong><em>,</em></strong><strong><em> </em></strong><strong><em> </em></strong><strong><em>numerator \:  \:  \: is \:  \:  \: in \:  \:  \: the \:  \:  \: form \:  \:  \:of \:  \:  \:  \\  {x}^{2}  +  {y}^{2}  = (x + y)(x - y) \\  \\  =  \frac{(cos \:  +  \: sin)(cos - sin)}{cos - sin} \\  \\</em></strong><strong><em> </em></strong><strong><em>Here</em></strong><strong><em>,</em></strong><strong><em> </em></strong><strong><em>(cos \:  - sin \: ) \: gets \:  \:  \: cancelled \\  \\  = cos \:  + sin \\  \\  = sin \:  +  \: cos \\  \\

= RHS

Hope its helpful ......

PLEASE MARK IT AS BRAINLIEST ......

Similar questions