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
\[ \frac{d}{dx}\left[\frac{\arctan\left(x\right)}{\frac{1}{x}}\right] = \frac{\frac{\frac{1}{x}}{1 + x^{2}} - \arctan\left(x\right) \frac{-1}{x^{2}}}{\frac{1}{x}^{2}} \]
\[ f(x) = \frac{\arctan\left(x\right)}{\frac{1}{x}} \]
\[ u = \arctan\left(x\right),\quad v = \frac{1}{x} \]
\[ u' = \frac{1}{1 + x^{2}},\quad v' = \frac{-1}{x^{2}} \]
\[ f'(x) = \frac{\left(\frac{1}{1 + x^{2}}\right)\left(\frac{1}{x}\right) - \left(\arctan\left(x\right)\right)\left(\frac{-1}{x^{2}}\right)}{\left(\frac{1}{x}\right)^{2}} \]
\[ f'(x) = \frac{\frac{\frac{1}{x}}{1 + x^{2}} - \arctan\left(x\right) \frac{-1}{x^{2}}}{\frac{1}{x}^{2}} \]
\[ f''(x) = \frac{\left(\frac{\frac{-1}{x^{2}} \left(1 + x^{2}\right) - \frac{2 x}{x}}{\left(1 + x^{2}\right)^{2}} - \left(\frac{\frac{-1}{x^{2}}}{1 + x^{2}} + \arctan\left(x\right) \frac{-\left(\left(-2\right) x\right)}{\left(x^{2}\right)^{2}}\right)\right) \frac{1}{x}^{2} - \left(\frac{\frac{1}{x}}{1 + x^{2}} - \arctan\left(x\right) \frac{-1}{x^{2}}\right) 2 \frac{1}{x} \frac{-1}{x^{2}}}{\left(\frac{1}{x}^{2}\right)^{2}} \]Values of f and f' for atan(x) / (1 / x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | 2.2142974 | -1.5071487 |
| -1 | 0.78539816 | -1.2853982 |
| 0.5 | 0.2318238 | 0.86364761 |
| 1 | 0.78539816 | 1.2853982 |
| 2 | 2.2142974 | 1.5071487 |
| 3 | 3.7471373 | 1.5490458 |
Questions
What is the derivative of atan(x) / (1 / x)?
The derivative of is .
What is the second derivative of atan(x) / (1 / x)?
(((-1 / * (1 + ) - 2x / x) / (1 + )^2 - (-1 / / (1 + ) + atan(x) * -(-2x) / ()^2)) * (1 / x)^2 - (1 / x / (1 + ) - atan(x) * -1 / ) * 2 * 1 / x * -1 / ) / ((1 / x)^2)^2.
Which rule do you use for atan(x) / (1 / x)?
The quotient rule.
What is the slope of atan(x) / (1 / x) at x = 1?
1.2853982.