Quartic Equation Solver

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Quartic Equation Solver

Quartic Equation Solver
\[\begin{aligned} x_1 &= -\frac{b}{4a}+\frac{S}{2}+\frac{1}{2}\sqrt{-4S^2-2p+\frac{q}{S}} \\ x_2 &= -\frac{b}{4a}+\frac{S}{2}-\frac{1}{2}\sqrt{-4S^2-2p+\frac{q}{S}} \\ x_3 &= -\frac{b}{4a}-\frac{S}{2}+\frac{1}{2}\sqrt{-4S^2-2p-\frac{q}{S}} \\ x_4 &= -\frac{b}{4a}-\frac{S}{2}-\frac{1}{2}\sqrt{-4S^2-2p-\frac{q}{S}} \end{aligned}\]

Variables

a = quartic coefficient
b = cubic coefficient
p = depressed quartic parameter
q = depressed quartic parameter
S = auxiliary solution term
x1 = first root
x2 = second root
x3 = third root
x4 = fourth root

Description

What is this formula?

This formula solves quartic equations of the form:


ax^4+bx^3+cx^2+dx+e=0


It uses Ferrari's method to calculate the four possible roots of a fourth-degree polynomial.


When to use it

Use this formula when solving fourth-degree polynomial equations in algebra and engineering problems.


Example

For:


x^4-5x²+4=0


The solutions are:


x=±1

x=±2


Applications

- Advanced algebra

- Engineering mathematics

- Control theory

- Physical modeling

- Numerical analysis


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