計算: ヴィエタの公式計算機
ヴィエタの公式計算機
係数を入力し、「三次関数を解く」をクリックして、ヴィエタの公式計算機 用にカスタマイズされた数学的出力を生成します。
Vieta’s Formulas Calculator
Discover the hidden geometry and arithmetic of your polynomial roots without ever having to actually calculate them. Vieta's Formula Calculator for Cubics instantly reveals the sums, paired products, and total properties of your roots directly from the starting coefficients.
ヴィエタの公式計算機
多項式係数を入力してください
What is it?
- Simple explanation: Mathematical shortcuts created by François Viète that prove how the coefficients of a polynomial strictly define the sum and product of its roots.
- Why it matters in cubic equations: It acts as an incredibly powerful verification tool. If you solve an equation, adding the three roots together *must* equal -b/a. If it doesn't, a mistake was made!
Formula / Method
- Formulas for Cubic Roots r_1, r_2, r_3: * Sum of roots: r_1 + r_2 + r_3 = -\frac{b}{a} * Pairwise product sum: r_1r_2 + r_1r_3 + r_2r_3 = \frac{c}{a} * Total product: r_1 \cdot r_2 \cdot r_3 = -\frac{d}{a}
How To Use
- Enter your standard equation coefficients: a, b, c, d.
- Click "Calculate Vieta Properties."
- Review the three generated outputs showing root relationships.
- Use these facts to verify your own hand-calculated roots.
Key Features
- Highly robust outputs formatted clearly.
- Instant generation without invoking deeper algorithms.
- Retains exact fraction formatting for pure accuracy.
- Useful for advanced geometric proofs and physics constraint analysis.
Example Concept
For 2x³ - 8x² + 6x - 4 = 0: Sum of roots = -(-8) / 2 = 4. Pairwise sum = 6 / 2 = 3. Product of roots = -(-4) / 2 = 2.
Ready to solve?
Run your numbers through our main interface and see instant results.
Open Cubic Equation SolverFrequently Asked Questions
3 次方程式とその解法に関するよくある質問に対する簡単な回答を見つけてください。
Does Vieta's rule apply to complex roots?
Yes! The rules of Vieta apply perfectly even when the roots involve imaginary numbers. The complex parts simply cancel each other out during addition.
Does this tell me what my roots actually are?
No, it only tells you how they relate to each other as a complete set.
Why is \(a\) in the denominator of everything?
Because Vieta's formulas inherently rely on normalizing the polynomial (making the leading coefficient 1) first.