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 product rule.
- 2
Product 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
\[ \frac{d}{dx}\left[\frac{1}{x} \arctan\left(x\right)\right] = \frac{-1}{x^{2}} \arctan\left(x\right) + \frac{\frac{1}{1 + x^{2}}}{x} \]
\[ f(x) = \frac{1}{x} \arctan\left(x\right) \]
\[ u = \frac{1}{x},\quad v = \arctan\left(x\right) \]
\[ u' = \frac{-1}{x^{2}},\quad v' = \frac{1}{1 + x^{2}} \]
\[ f'(x) = \left(\frac{-1}{x^{2}}\right)\left(\arctan\left(x\right)\right) + \left(\frac{1}{x}\right)\left(\frac{1}{1 + x^{2}}\right) \]
\[ f'(x) = \frac{-1}{x^{2}} \arctan\left(x\right) + \frac{\frac{1}{1 + x^{2}}}{x} \]
\[ f''(x) = \frac{-\left(\left(-2\right) x\right)}{\left(x^{2}\right)^{2}} \arctan\left(x\right) + \frac{-1}{x^{2}} \frac{1}{1 + x^{2}} + \frac{\frac{-\left(2 x\right)}{\left(1 + x^{2}\right)^{2}} x - \frac{1}{1 + x^{2}}}{x^{2}} \]Values of f and f' for 1 / x * atan(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | 0.55357436 | 0.17678718 |
| -1 | 0.78539816 | 0.28539816 |
| 0.5 | 0.92729522 | -0.25459044 |
| 1 | 0.78539816 | -0.28539816 |
| 2 | 0.55357436 | -0.17678718 |
| 3 | 0.41634859 | -0.10544953 |
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 + )) / .
Which rule do you use for 1 / x * atan(x)?
The product rule.
What is the slope of 1 / x * atan(x) at x = 1?
-0.28539816.