derivative of arctan(x/(sqrt(1-x^2)))

解

\frac{d}{d x} (arctan (\frac{x}{1 - x ^{2}}))

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

解答ステップ

\frac{d}{d x} (arctan (\frac{x}{1 - x ^{2}}))

連鎖法則を適用:

\frac{1}{( \frac{x}{1 - x ^{2}} ) ^{2} + 1} \frac{d}{d x} (\frac{x}{1 - x ^{2}})

= \frac{1}{( \frac{x}{1 - x ^{2}} ) ^{2} + 1} \frac{d}{d x} (\frac{x}{1 - x ^{2}})

\frac{d}{d x} (\frac{x}{1 - x ^{2}}) = \frac{1}{( 1 - x ^{2} ) 1 - x ^{2}}

= \frac{1}{( \frac{x}{1 - x ^{2}} ) ^{2} + 1} \cdot \frac{1}{( 1 - x ^{2} ) 1 - x ^{2}}

簡素化

\frac{1}{( \frac{x}{1 - x ^{2}} ) ^{2} + 1} \cdot \frac{1}{( 1 - x ^{2} ) 1 - x ^{2}} : \frac{1}{1 - x ^{2}}

= \frac{1}{1 - x ^{2}}