Derivative Calculator
Powers ^ · multiply with * or a space · sqrt( ) ln( ) log( ) sin( ) cos( ) tan( ) e pi |x| · implicit products like 2x or x sin x work
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Derivative
Accepts numbers and constants such as pi/2 or e
Derivative
3x^2 - 4At x = 2
The function is increasing at this point: near x = 2, f changes by about 8 for every unit step in x.
Graph
Where f′(x) = 0 (searched from x = -8 to 12)
- x ≈ -1.1547, f ≈ 4.0792: local maximum
- x ≈ 1.1547, f ≈ -2.0792: local minimum
Term by term
Rules used
- Sum and difference rule
- Power rule
- Constant multiple rule
Differentiate a function of x symbolically using the power, product, quotient and chain rules. Take the first, second or third derivative, evaluate it at a point, and graph f and f′ together to see where the function rises, falls and turns.
Formula
Worked Example
By the product rule with u = x² and v = sin x, f′ = 2x · sin x + x² · cos x. At x = π, sin π = 0 and cos π = −1, so f′(π) = −π²: the function is falling steeply there.
Frequently Asked Questions
What are the basic rules of differentiation?
Power rule: (xⁿ)′ = nxⁿ⁻¹. Product rule: (uv)′ = u′v + uv′. Quotient rule: (u/v)′ = (u′v − uv′)/v². Chain rule: (f(g(x)))′ = f′(g(x)) · g′(x). Standard results: (sin x)′ = cos x, (cos x)′ = −sin x, (eˣ)′ = eˣ and (ln x)′ = 1/x.
What does the derivative tell you about a graph?
Its sign shows whether the function is increasing (f′ > 0) or decreasing (f′ < 0), and its zeros mark possible maxima and minima. The second derivative gives the concavity: f″ > 0 curves upward and f″ < 0 downward.
How do you differentiate x to the power x?
Write xˣ as e^(x ln x) and apply the chain rule: (xˣ)′ = xˣ(ln x + 1). This logarithmic differentiation works whenever both the base and the exponent depend on x.
Common Mistakes
- !Forgetting the chain rule: the derivative of sin(3x) is 3cos(3x), not cos(3x).
- !Using the power rule on an exponential: the derivative of 2ˣ is 2ˣ ln 2, not x·2ˣ⁻¹.