Question

cos(2tan-1(x))

Answer 1

i think u know the formula \[2 \tan^{-1}x=\tan^{-1} \frac{ 2x }{ 1-x ^{2} } \]

Answer 2

so\[\cos (2 \tan^{-1} x)=\cos \tan^{-1} \frac{ 2x }{ 1-x ^{2} }\]

Answer 3

now let \[\tan^{-1} \frac{ 2x }{ 1-x ^{2} } = \theta\]

Answer 4

\[\tan \theta =\frac{ 2x }{ 1-x ^{2} }\]

Answer 5

now i wanna draw a triangle for \[\tan \theta\]

Answer 6

we know\[\tan \theta =\frac{ AB }{ OB}\]

Answer 7

r u following me

Answer 8

ok i just telling u the result\[\frac{ 1-x ^{2} }{ 1+x ^{2} }\]