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📐 Quadratic Axis And Vertex And Roots All In One 計算機

專業免費的 Quadratic Axis And Vertex And Roots All In One 計算機。純前端本機毫秒級計算、零資料上傳、極致隱私保護。提供詳細公式推導、實例示範與常見問答。

即時推算結果 (Computed Output)
(1.5,-0.25) Axis of symmetry: x = 1.5
專業公認計算模型,即時運算完畢
📜 計算歷史記錄 (試算軌跡)
尚無歷史記錄,每次點擊「計算」將在此留下試算軌跡...

What this calculator does

This Quadratic Function Analyzer takes any quadratic in standard form, f(x) = ax² + bx + c, and instantly returns its complete profile: the vertex, the axis of symmetry, the discriminant, the real roots (x-intercepts), and the y-intercept. It is a universal math tool that works for parabolas in algebra, precalculus, physics projectile problems, and optimization.

How to use it

Enter the three coefficients a, b, and c. The coefficient a must be nonzero for a true quadratic (if a = 0 the equation is linear). Press calculate and read off every key feature of the parabola in one view.

The formulas explained

The axis of symmetry and the vertex share the same x-value:

x = ((-b) ÷ (2a))
Plug that x back into the function to get the vertex y-value. The roots come from the quadratic formula,
x = ((-b ± \sqrt{b^{2} - 4ac}) ÷ (2a))
The quantity under the root, b^{2} - 4ac, is the discriminant: if it is positive there are two real roots, if it is zero there is one repeated root, and if it is negative there are no real roots (the parabola never crosses the x-axis). The y-intercept is simply c, since f(0) = c.

Worked example

For f(x) = x^{2} - 3x + 2 (a = 1, b = −3, c = 2): axis

x = ((-(-3)) ÷ (2 · 1)) = 1.5
vertex
y = 1.5^{2} - 3(1.5) + 2 = -0.25
so the vertex is (1.5, -0.25). Discriminant = 9 - 8 = 1, giving roots
x = ((3 ± 1) ÷ (2)) = 2 and 1
The y-intercept is (0, 2).

使用注意事項與精準校對原則(6 大核心守則)

📐 1. 嚴格對齊輸入量綱與單位

輸入各項數值時請務必確認量綱(例如小時、天數、金額、百分比),避免單位不匹配引發推算偏差。

🔒 2. 純前端本機毫秒級隱私保障

所有計算邏輯 100% 在您的終端瀏覽器內完成,資料絕不上傳伺服器,嚴格守護商業與個人隱私。

📊 3. 符合公認學術與產業計算模型

演算法嚴格遵循國際通用數學公式與標準計算模型,經多重情境交叉核對,數值嚴密精確。

📋 4. 一鍵複製與免登入 PDF 匯出

支援一鍵複製推算結果字串至剪貼簿,亦可直接點擊列印按鈕輸出純淨 PDF 工作報表。

🔄 5. 多情景敏感度動態對比

建議針對極端值與多組預期情景分別試算,觀察輸出數據的波動區間,輔助做出更穩健的決策。

🛡️ 6. 專業諮詢與日常參考免責聲明

本工具運算結果供日常排程、學業研習與事前參考之用,如涉及重大法規或投資決策請諮詢持證專家。

常見問題 (FAQ)

What if a = 0?
The expression becomes linear (bx + c) and has at most one root; there is no parabola or vertex.
What does a negative discriminant mean?
The parabola does not touch the x-axis, so there are no real roots — only complex ones.
Does the vertex x always equal the axis of symmetry?
Yes. The axis of symmetry is the vertical line through the vertex, \(x = \frac{-b}{2a}\).