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
\[ \frac{d}{dx}\left[\tan\left(x\right) \arctan\left(x\right)\right] = \frac{\arctan\left(x\right)}{\cos\left(x\right)^{2}} + \tan\left(x\right) \frac{1}{1 + x^{2}} \]
\[ f(x) = \tan\left(x\right) \arctan\left(x\right) \]
\[ u = \tan\left(x\right),\quad v = \arctan\left(x\right) \]
\[ u' = \frac{1}{\cos\left(x\right)^{2}},\quad v' = \frac{1}{1 + x^{2}} \]
\[ f'(x) = \left(\frac{1}{\cos\left(x\right)^{2}}\right)\left(\arctan\left(x\right)\right) + \left(\tan\left(x\right)\right)\left(\frac{1}{1 + x^{2}}\right) \]
\[ f'(x) = \frac{\arctan\left(x\right)}{\cos\left(x\right)^{2}} + \tan\left(x\right) \frac{1}{1 + x^{2}} \]
\[ f''(x) = \frac{\frac{\cos\left(x\right)^{2}}{1 + x^{2}} - \arctan\left(x\right) 2 \cos\left(x\right) -\sin\left(x\right)}{\left(\cos\left(x\right)^{2}\right)^{2}} + \frac{\frac{1}{1 + x^{2}}}{\cos\left(x\right)^{2}} + \tan\left(x\right) \frac{-\left(2 x\right)}{\left(1 + x^{2}\right)^{2}} \]Values of f and f' for tan(x) * atan(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -2.4191641 | -5.9561107 |
| -1 | 1.2231852 | -3.4691001 |
| 0.5 | 0.25329184 | 1.0390636 |
| 1 | 1.2231852 | 3.4691001 |
| 2 | -2.4191641 | 5.9561107 |
| 3 | -0.17804716 | 1.2601711 |
Questions
What is the derivative of tan(x) * atan(x)?
The derivative of is .
What is the second derivative of tan(x) * atan(x)?
(cos(x)^2 / (1 + ) - atan(x) * 2cos(x) * -sin(x)) / (cos(x)^2)^2 + 1 / (1 + ) / cos(x)^2 + tan(x) * -(2x) / (1 + )^2.
Which rule do you use for tan(x) * atan(x)?
The product rule.
What is the slope of tan(x) * atan(x) at x = 1?
3.4691001.