Derivative of
The derivative of is .
f(x) =
Type any function of x; the derivative is computed symbolically in your browser.
How to work it out
- 1
We differentiate with respect to x. The rule that applies is the quotient rule.
- 2
Quotient rule: . Let and .
- 3
Differentiate each piece:
- 4
Put them in the rule:
- 5
Simplify:
- 6
Differentiating once more gives the second derivative, which tells you about curvature:
LaTeX source of the formulas on this page
\[ \frac{d}{dx}\left[\frac{\frac{1}{x}}{\arctan\left(x\right)}\right] = \frac{\frac{-1}{x^{2}} \arctan\left(x\right) - \frac{\frac{1}{1 + x^{2}}}{x}}{\arctan\left(x\right)^{2}} \]
\[ f(x) = \frac{\frac{1}{x}}{\arctan\left(x\right)} \]
\[ u = \frac{1}{x},\quad v = \arctan\left(x\right) \]
\[ u' = \frac{-1}{x^{2}},\quad v' = \frac{1}{1 + x^{2}} \]
\[ f'(x) = \frac{\left(\frac{-1}{x^{2}}\right)\left(\arctan\left(x\right)\right) - \left(\frac{1}{x}\right)\left(\frac{1}{1 + x^{2}}\right)}{\left(\arctan\left(x\right)\right)^{2}} \]
\[ f'(x) = \frac{\frac{-1}{x^{2}} \arctan\left(x\right) - \frac{\frac{1}{1 + x^{2}}}{x}}{\arctan\left(x\right)^{2}} \]
\[ f''(x) = \frac{\left(\frac{-\left(\left(-2\right) x\right)}{\left(x^{2}\right)^{2}} \arctan\left(x\right) + \frac{-1}{x^{2}} \frac{1}{1 + x^{2}} - \frac{\frac{-\left(2 x\right)}{\left(1 + x^{2}\right)^{2}} x - \frac{1}{1 + x^{2}}}{x^{2}}\right) \arctan\left(x\right)^{2} - \left(\frac{-1}{x^{2}} \arctan\left(x\right) - \frac{\frac{1}{1 + x^{2}}}{x}\right) 2 \arctan\left(x\right) \frac{1}{1 + x^{2}}}{\left(\arctan\left(x\right)^{2}\right)^{2}} \]Values of f and f' for 1 / x / atan(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | 0.45161051 | 0.30738608 |
| -1 | 1.2732395 | 2.083809 |
| 0.5 | 4.3136209 | -16.070172 |
| 1 | 1.2732395 | -2.083809 |
| 2 | 0.45161051 | -0.30738608 |
| 3 | 0.26687039 | -0.11032274 |
Questions
What is the derivative of 1 / x / atan(x)?
The derivative of is .
What is the second derivative of 1 / x / atan(x)?
((-(-2x) / ()^2 * atan(x) + -1 / * 1 / (1 + ) - (-(2x) / (1 + )^2 * x - 1 / (1 + )) / ) * atan(x)^2 - (-1 / * atan(x) - 1 / (1 + ) / x) * 2atan(x) * 1 / (1 + )) / (atan(x)^2)^2.
Which rule do you use for 1 / x / atan(x)?
The quotient rule.
What is the slope of 1 / x / atan(x) at x = 1?
-2.083809.