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
\[ \frac{d}{dx}\left[\frac{x^{4}}{x^{5}}\right] = \frac{4 x^{3} x^{5} - x^{4} 5 x^{4}}{\left(x^{5}\right)^{2}} \]
\[ f(x) = \frac{x^{4}}{x^{5}} \]
\[ u = x^{4},\quad v = x^{5} \]
\[ u' = 4 x^{3},\quad v' = 5 x^{4} \]
\[ f'(x) = \frac{\left(4 x^{3}\right)\left(x^{5}\right) - \left(x^{4}\right)\left(5 x^{4}\right)}{\left(x^{5}\right)^{2}} \]
\[ f'(x) = \frac{4 x^{3} x^{5} - x^{4} 5 x^{4}}{\left(x^{5}\right)^{2}} \]
\[ f''(x) = \frac{\left(12 x^{2} x^{5} + 4 x^{3} 5 x^{4} - \left(4 x^{3} 5 x^{4} + x^{4} 20 x^{3}\right)\right) \left(x^{5}\right)^{2} - \left(4 x^{3} x^{5} - x^{4} 5 x^{4}\right) 2 x^{5} 5 x^{4}}{\left(\left(x^{5}\right)^{2}\right)^{2}} \]Values of f and f' for /
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -0.5 | -0.25 |
| -1 | -1 | -1 |
| 0.5 | 2 | -4 |
| 1 | 1 | -1 |
| 2 | 0.5 | -0.25 |
| 3 | 0.33333333 | -0.11111111 |
Questions
What is the derivative of / ?
The derivative of is .
What is the second derivative of / ?
((12 * * + 4 * * 5 * - (4 * * 5 * + * 20 * )) * ()^2 - (4 * * - * 5 * ) * 2 * * 5 * ) / (()^2)^2.
Which rule do you use for / ?
The quotient rule.
What is the slope of / at x = 1?
-1.