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Calculate permutations P(n), combinations C(n,k), arrangements V(n,k) and their with-repetition variants. Formulas and examples. Free online combinatorics calculator.
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Polynomial Derivative Calculator
The polynomial derivative calculator finds the derivative of any polynomial up to degree 4 in seconds. Enter the coefficients a0..a4 of W(x) = a0 + a1*x + a2*x^2 + a3*x^3 + a4*x^4, and the calculator applies the power rule to produce a readable derivative formula. Optionally provide a value for x to get the numeric value of the derivative at that point — useful for finding the slope of the tangent line or studying the monotonicity of a function.
How we calculate the derivative
For W(x) = a0 + a1*x + a2*x^2 + a3*x^3 + a4*x^4 we apply the power rule d/dx(a_n * x^n) = n * a_n * x^(n-1) to each term: W'(x) = a1 + 2*a2*x + 3*a3*x^2 + 4*a4*x^3. If you provide an x value, the calculator substitutes it into the derivative formula.
Example: derivative of 3x^2 + 2x + 1
Coefficients: a0=1, a1=2, a2=3. Polynomial: 3x^2 + 2x + 1. Applying the power rule: derivative of 2x is 2, derivative of 3x^2 is 6x. Result: W'(x) = 6x + 2. At x=1: W'(1) = 8.
Frequently asked questions
What is the derivative of a polynomial?
The derivative of a polynomial is a polynomial of one lower degree, obtained by applying the power rule to each term. It describes the rate of change of the polynomial with respect to x.
How does the power rule work?
The power rule states that the derivative of a*x^n is n*a*x^(n-1). For example, the derivative of 5x^3 is 15x^2. We apply it independently to each term of the polynomial.
What happens to the constant term when differentiating?
The constant term disappears after differentiation because the derivative of a constant is 0. This follows from the power rule: d/dx(c) = d/dx(c*x^0) = 0*c*x^(-1) = 0.
How does the calculator compute the derivative of a degree-4 polynomial?
The calculator takes coefficients a0..a4 and applies the power rule: W'(x) = a1 + 2*a2*x + 3*a3*x^2 + 4*a4*x^3.
What is the "x value" field for?
If you enter a value for x, the calculator evaluates W'(x) numerically at that point — for example, to find the slope of the tangent line to the curve at x.
What is the derivative of a constant polynomial?
The derivative of any constant is 0. If W(x) = c, then W'(x) = 0, since a constant does not change with respect to x.
Does the calculator handle negative coefficients?
Yes. You can enter negative coefficients for any degree. The calculator correctly applies the power rule and displays the result with the appropriate sign.
How can I verify the calculated derivative?
Set x=0 and check that W'(0) equals the coefficient a1. You can also use a simple polynomial such as x^2 and verify that the derivative is 2x.
What is a practical use case for a polynomial derivative?
If W(x) describes the position of an object over time, W'(x) is its instantaneous velocity. In economics, the derivative of the cost function is marginal cost. In geometry, W'(x0) is the slope of the tangent at x0.
Does the calculator handle the zero polynomial?
Yes. If all coefficients are 0, the calculator displays "0" as both the polynomial and derivative formulas, and returns 0 as the numeric value at any point.
Indicative result
This calculator is intended for educational use and symbolic computation of polynomials up to degree 4. Results are accurate for integer and real coefficients within JavaScript floating-point range.
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