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
\[ \frac{d}{dx}\left[\frac{\cos\left(x\right)}{x^{2}}\right] = \frac{-\left(\sin\left(x\right) x^{2}\right) - \cos\left(x\right) 2 x}{\left(x^{2}\right)^{2}} \]
\[ f(x) = \frac{\cos\left(x\right)}{x^{2}} \]
\[ u = \cos\left(x\right),\quad v = x^{2} \]
\[ u' = -\sin\left(x\right),\quad v' = 2 x \]
\[ f'(x) = \frac{\left(-\sin\left(x\right)\right)\left(x^{2}\right) - \left(\cos\left(x\right)\right)\left(2 x\right)}{\left(x^{2}\right)^{2}} \]
\[ f'(x) = \frac{-\left(\sin\left(x\right) x^{2}\right) - \cos\left(x\right) 2 x}{\left(x^{2}\right)^{2}} \]
\[ f''(x) = \frac{\left(-\left(\cos\left(x\right) x^{2} + \sin\left(x\right) 2 x\right) - \left(-\left(\sin\left(x\right) 2 x\right) + 2 \cos\left(x\right)\right)\right) \left(x^{2}\right)^{2} - \left(-\left(\sin\left(x\right) x^{2}\right) - \cos\left(x\right) 2 x\right) 2 x^{2} 2 x}{\left(\left(x^{2}\right)^{2}\right)^{2}} \]Values of f and f' for cos(x) /
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -0.10403671 | 0.12328765 |
| -1 | 0.54030231 | 1.9220756 |
| 0.5 | 3.5103302 | -15.959023 |
| 1 | 0.54030231 | -1.9220756 |
| 2 | -0.10403671 | -0.12328765 |
| 3 | -0.10999917 | 0.057652777 |
Questions
What is the derivative of cos(x) / ?
The derivative of is .
What is the second derivative of cos(x) / ?
((-(cos(x) * + sin(x) * 2x) - (-(sin(x) * 2x) + 2cos(x))) * ()^2 - (-(sin(x) * ) - cos(x) * 2x) * 2 * * 2x) / (()^2)^2.
Which rule do you use for cos(x) / ?
The quotient rule.
What is the slope of cos(x) / at x = 1?
-1.9220756.