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
\[ \frac{d}{dx}\left[\frac{\frac{1}{x}}{\cos\left(x\right)}\right] = \frac{\frac{-1}{x^{2}} \cos\left(x\right) - \frac{-\sin\left(x\right)}{x}}{\cos\left(x\right)^{2}} \]
\[ f(x) = \frac{\frac{1}{x}}{\cos\left(x\right)} \]
\[ u = \frac{1}{x},\quad v = \cos\left(x\right) \]
\[ u' = \frac{-1}{x^{2}},\quad v' = -\sin\left(x\right) \]
\[ f'(x) = \frac{\left(\frac{-1}{x^{2}}\right)\left(\cos\left(x\right)\right) - \left(\frac{1}{x}\right)\left(-\sin\left(x\right)\right)}{\left(\cos\left(x\right)\right)^{2}} \]
\[ f'(x) = \frac{\frac{-1}{x^{2}} \cos\left(x\right) - \frac{-\sin\left(x\right)}{x}}{\cos\left(x\right)^{2}} \]
\[ f''(x) = \frac{\left(\frac{-\left(\left(-2\right) x\right)}{\left(x^{2}\right)^{2}} \cos\left(x\right) + \frac{-1}{x^{2}} -\sin\left(x\right) - \frac{-\left(\cos\left(x\right) x\right) - -\sin\left(x\right)}{x^{2}}\right) \cos\left(x\right)^{2} - \left(\frac{-1}{x^{2}} \cos\left(x\right) - \frac{-\sin\left(x\right)}{x}\right) 2 \cos\left(x\right) -\sin\left(x\right)}{\left(\cos\left(x\right)^{2}\right)^{2}} \]Values of f and f' for 1 / x / cos(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | 1.201499 | 3.2260727 |
| -1 | -1.8508157 | 1.031659 |
| 0.5 | 2.2789879 | -3.312959 |
| 1 | 1.8508157 | 1.031659 |
| 2 | -1.201499 | 3.2260727 |
| 3 | -0.33670289 | 0.16023013 |
Questions
What is the derivative of 1 / x / cos(x)?
The derivative of is .
What is the second derivative of 1 / x / cos(x)?
((-(-2x) / ()^2 * cos(x) + -1 / * -sin(x) - (-(cos(x) * x) - -sin(x)) / ) * cos(x)^2 - (-1 / * cos(x) - -sin(x) / x) * 2cos(x) * -sin(x)) / (cos(x)^2)^2.
Which rule do you use for 1 / x / cos(x)?
The quotient rule.
What is the slope of 1 / x / cos(x) at x = 1?
1.031659.