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
\[ \frac{d}{dx}\left[x^{2} \cos\left(x\right)\right] = 2 x \cos\left(x\right) + x^{2} -\sin\left(x\right) \]
\[ f(x) = x^{2} \cos\left(x\right) \]
\[ u = x^{2},\quad v = \cos\left(x\right) \]
\[ u' = 2 x,\quad v' = -\sin\left(x\right) \]
\[ f'(x) = \left(2 x\right)\left(\cos\left(x\right)\right) + \left(x^{2}\right)\left(-\sin\left(x\right)\right) \]
\[ f'(x) = 2 x \cos\left(x\right) + x^{2} -\sin\left(x\right) \]
\[ f''(x) = 2 \cos\left(x\right) + 2 x -\sin\left(x\right) + 2 x -\sin\left(x\right) + x^{2} -\cos\left(x\right) \]Values of f and f' for * cos(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -1.6645873 | 5.3017771 |
| -1 | 0.54030231 | -0.23913363 |
| 0.5 | 0.21939564 | 0.75772618 |
| 1 | 0.54030231 | 0.23913363 |
| 2 | -1.6645873 | -5.3017771 |
| 3 | -8.9099325 | -7.2100351 |
Questions
What is the derivative of * cos(x)?
The derivative of is .
What is the second derivative of * cos(x)?
2cos(x) + 2x * -sin(x) + 2x * -sin(x) + * -cos(x).
Which rule do you use for * cos(x)?
The product rule.
What is the slope of * cos(x) at x = 1?
0.23913363.