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
\[ \frac{d}{dx}\left[\frac{\arctan\left(x\right)}{x^{3}}\right] = \frac{\frac{x^{3}}{1 + x^{2}} - \arctan\left(x\right) 3 x^{2}}{\left(x^{3}\right)^{2}} \]
\[ f(x) = \frac{\arctan\left(x\right)}{x^{3}} \]
\[ u = \arctan\left(x\right),\quad v = x^{3} \]
\[ u' = \frac{1}{1 + x^{2}},\quad v' = 3 x^{2} \]
\[ f'(x) = \frac{\left(\frac{1}{1 + x^{2}}\right)\left(x^{3}\right) - \left(\arctan\left(x\right)\right)\left(3 x^{2}\right)}{\left(x^{3}\right)^{2}} \]
\[ f'(x) = \frac{\frac{x^{3}}{1 + x^{2}} - \arctan\left(x\right) 3 x^{2}}{\left(x^{3}\right)^{2}} \]
\[ f''(x) = \frac{\left(\frac{3 x^{2} \left(1 + x^{2}\right) - x^{3} 2 x}{\left(1 + x^{2}\right)^{2}} - \left(\frac{3 x^{2}}{1 + x^{2}} + \arctan\left(x\right) 6 x\right)\right) \left(x^{3}\right)^{2} - \left(\frac{x^{3}}{1 + x^{2}} - \arctan\left(x\right) 3 x^{2}\right) 2 x^{3} 3 x^{2}}{\left(\left(x^{3}\right)^{2}\right)^{2}} \]Values of f and f' for atan(x) /
| x | f(x) | f'(x) |
|---|---|---|
| -2 | 0.13839359 | 0.18259038 |
| -1 | 0.78539816 | 1.8561945 |
| 0.5 | 3.7091809 | -15.855085 |
| 1 | 0.78539816 | -1.8561945 |
| 2 | 0.13839359 | -0.18259038 |
| 3 | 0.046260955 | -0.042557251 |
Questions
What is the derivative of atan(x) / ?
The derivative of is .
What is the second derivative of atan(x) / ?
(((3 * * (1 + ) - * 2x) / (1 + )^2 - (3 * / (1 + ) + atan(x) * 6x)) * ()^2 - ( / (1 + ) - atan(x) * 3 * ) * 2 * * 3 * ) / (()^2)^2.
Which rule do you use for atan(x) / ?
The quotient rule.
What is the slope of atan(x) / at x = 1?
-1.8561945.