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
\[ \frac{d}{dx}\left[\cos\left(x\right) \tan\left(x\right)\right] = -\left(\sin\left(x\right) \tan\left(x\right)\right) + \cos\left(x\right) \frac{1}{\cos\left(x\right)^{2}} \]
\[ f(x) = \cos\left(x\right) \tan\left(x\right) \]
\[ u = \cos\left(x\right),\quad v = \tan\left(x\right) \]
\[ u' = -\sin\left(x\right),\quad v' = \frac{1}{\cos\left(x\right)^{2}} \]
\[ f'(x) = \left(-\sin\left(x\right)\right)\left(\tan\left(x\right)\right) + \left(\cos\left(x\right)\right)\left(\frac{1}{\cos\left(x\right)^{2}}\right) \]
\[ f'(x) = -\left(\sin\left(x\right) \tan\left(x\right)\right) + \cos\left(x\right) \frac{1}{\cos\left(x\right)^{2}} \]
\[ f''(x) = -\left(\cos\left(x\right) \tan\left(x\right) + \sin\left(x\right) \frac{1}{\cos\left(x\right)^{2}}\right) + -\left(\sin\left(x\right) \frac{1}{\cos\left(x\right)^{2}}\right) + \cos\left(x\right) \frac{-\left(2 \cos\left(x\right) -\sin\left(x\right)\right)}{\left(\cos\left(x\right)^{2}\right)^{2}} \]Values of f and f' for cos(x) * tan(x)
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -0.90929743 | -0.41614684 |
| -1 | -0.84147098 | 0.54030231 |
| 0.5 | 0.47942554 | 0.87758256 |
| 1 | 0.84147098 | 0.54030231 |
| 2 | 0.90929743 | -0.41614684 |
| 3 | 0.14112001 | -0.9899925 |
Questions
What is the derivative of cos(x) * tan(x)?
The derivative of is .
What is the second derivative of cos(x) * tan(x)?
-(cos(x) * tan(x) + sin(x) * 1 / cos(x)^2) + -(sin(x) * 1 / cos(x)^2) + cos(x) * -(2cos(x) * -sin(x)) / (cos(x)^2)^2.
Which rule do you use for cos(x) * tan(x)?
The product rule.
What is the slope of cos(x) * tan(x) at x = 1?
0.54030231.