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Prove that:tan4x = 4tanx(1-tan²x) / 1-6tan²x + tan⁴xPlz...No fake answersIt's urgent...​

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ANSWER:

Taking LHS tan 4x

we know that

tan 2x =

\frac{2tanx}{1 -  {tan \: }^{2} x}

replacing x with 2x

tan (2 × 2x)=

\frac{2tan \: 2x}{1 -  {tan}^{2} 2x}

USING tan2x =

\frac{2tanx}{1 -  {tan}^{2}x }

2 \times \frac{2tanx}{1 -  {tan}^{2} x} \div 1 -  \frac{2tanx}{1 -  {tan}^{2}x } {}^{2}

\frac{4tanx}{1} \times  \frac{1 -  {tan}^{2}x }{1 -  {{tan }^{2}x} ^{2}  }  -  {4tan}^{2}x

using (a-b)=

{a}^{2} +  {b}^{2} - 2ab

\frac{4tanx(1 -  {tan}^{2}x) }{( {1}^{2} + ( {tan}^{2} {x})^{2} - 2 \times 1 \times  {tan}^{2}x  } - 4 {tan}^{2}x

\frac{4tanx(1 -  {tan}^{2}x) }{1 +  {tan}^{4}x - 6 {tan}^{4}x }

= RHS

LHS=RHS



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