Math, asked by shivamkumarsah2002, 8 months ago

sinA(1+tanA)+cosA(1+cotA) = secA+cosec​

Answers

Answered by Anonymous
5

Solution:-

Given

  \rm  :  \implies{  \sin  A (1 +  \tan  A) +  \cos A(1 +  \cot A)}

To prove

 \rm \:  :  \implies \:  \sec A +  \csc A

Using some trigonometry identities

 \rm \to \:  \tan A =  \dfrac{ \sin A}{ \cos A}

 \rm \to \cot A =  \dfrac{ \cos A}{ \sin A}

Put the value on

\rm  :  \implies{  \sin  A (1 +  \tan  A) +  \cos A(1 +  \cot A)}

 \rm  : \implies \sin A \bigg(1 +  \dfrac{ \sin A}{ \cos A}  \bigg ) +  \cos A \bigg(1 +  \dfrac{  \cos A}{ \sin A}  \bigg)

Taking lcm

\rm  : \implies \sin A \bigg(  \dfrac{  \cos  A + \sin A}{ \cos A}  \bigg ) +  \cos A \bigg(  \dfrac{   \sin A + \cos A}{ \sin A}  \bigg)

\rm  : \implies   \dfrac{   \sin  A \cos  A + \sin {}^{2}  A}{ \cos A}  +   \dfrac{   \sin A  \cos A + \cos {}^{2}  A}{ \sin A}

\rm  : \implies   \dfrac{   \sin \: A( \sin  A \cos  A + \sin {}^{2}  A) +  \cos A(\sin A  \cos A + \cos {}^{2}  A)}{  \sin  A \cos A}

\rm  : \implies   \dfrac{   \sin {}^{2}   A \cos  A + \sin {}^{3}  A+  \sin A  \cos  {}^{2} A + \cos {}^{3}  A}{  \sin  A \cos A}

\rm  : \implies   \dfrac{   \sin {}^{2}   A \cos  A  +  \cos {}^{3}A + \sin {}^{3}  A+  \sin A  \cos  {}^{2} A }{  \sin  A \cos A}

\rm  : \implies   \dfrac{   \cos  A  (\sin {}^{2}   A   +  \cos {}^{2}A) +  \sin  A( \sin {}^{2}  A+  \cos  {}^{2} A )}{  \sin  A \cos A}

 \rm :  \implies \dfrac{ \cos A +  \sin A}{ \sin  A \cos A }

 \rm  : \implies \dfrac{ \cos A}{\sin  A \cos A}  +  \dfrac{ \sin A}{\sin  A \cos A}

 \rm :  \implies \:  \dfrac{1}{ \sin A}  +  \dfrac{1}{ \cos A }

 \rm :  \implies \:  \sec A +  \csc A

Hence proved

Answered by bananiadak1978
2

see my memo attachment mate ♥️

hope it's help you ☺️

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