Derivative of
The derivative of is \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}}.
f(x) =
\frac{d}{dx}\left[\frac{\sin\left(x\right)}{e^{x}}\right] = \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}}
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:
f'(x) = \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}} - 6
Differentiating once more gives the second derivative, which tells you about curvature:
f''(x) = \frac{\left(-\left(\sin\left(x\right) e^{x}\right) + \cos\left(x\right) e^{x} - \left(\cos\left(x\right) e^{x} + \sin\left(x\right) e^{x}\right)\right) e^{x}^{2} - \left(\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}\right) 2 e^{x} e^{x}}{\left(e^{x}^{2}\right)^{2}}
LaTeX source of the formulas on this page
\[ \frac{d}{dx}\left[\frac{\sin\left(x\right)}{e^{x}}\right] = \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}} \]
\[ f(x) = \frac{\sin\left(x\right)}{e^{x}} \]
\[ u = \sin\left(x\right),\quad v = e^{x} \]
\[ u' = \cos\left(x\right),\quad v' = e^{x} \]
\[ f'(x) = \frac{\left(\cos\left(x\right)\right)\left(e^{x}\right) - \left(\sin\left(x\right)\right)\left(e^{x}\right)}{\left(e^{x}\right)^{2}} \]
\[ f'(x) = \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}} \]
\[ f''(x) = \frac{\left(-\left(\sin\left(x\right) e^{x}\right) + \cos\left(x\right) e^{x} - \left(\cos\left(x\right) e^{x} + \sin\left(x\right) e^{x}\right)\right) e^{x}^{2} - \left(\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}\right) 2 e^{x} e^{x}}{\left(e^{x}^{2}\right)^{2}} \]Values of f and f' for sin(x) / exp(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -6.7188497 | 3.6439174 |
| -1 | -2.2873553 | 3.7560492 |
| 0.5 | 0.29078629 | 0.24149444 |
| 1 | 0.30955988 | -0.11079377 |
| 2 | 0.12306002 | -0.17937937 |
| 3 | 0.0070259515 | -0.056314776 |
Questions
What is the derivative of sin(x) / exp(x)?
The derivative of is \frac{\cos\left(x\right) e^{x} - \sin\left(x\right) e^{x}}{e^{x}^{2}}.
What is the second derivative of sin(x) / exp(x)?
((-(sin(x) * exp(x)) + cos(x) * exp(x) - (cos(x) * exp(x) + sin(x) * exp(x))) * exp(x)^2 - (cos(x) * exp(x) - sin(x) * exp(x)) * 2exp(x) * exp(x)) / (exp(x)^2)^2.
Which rule do you use for sin(x) / exp(x)?
The quotient rule.
What is the slope of sin(x) / exp(x) at x = 1?
-0.11079377.