在線即時計算器 · 純前端本地秒算 · 零數據上傳

📐 Difference Of Two Squares 計算機

專業免費的 Difference Of Two Squares 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)
40 = (a + b)(a − b)
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 Is the Difference of Two Squares?

The difference of two squares is one of the most important algebraic identities. For any two numbers a and b, the expression a^2 - b^2 can always be factored into the product (a + b)(a - b). This calculator evaluates both the numeric result and shows the factored form, making it useful for checking homework, factoring polynomials, and mental-math shortcuts.

How to Use the Calculator

Enter your first value a and your second value b. The tool computes a^2, b^2, their difference, and the two factors (a + b) and (a - b). Values can be whole numbers, decimals, or negatives.

The Formula Explained

The identity comes from expanding the product:

(a + b)(a - b) = a^2 - ab + ab - b^2 = a^2 - b^2

The two middle terms cancel, leaving only a^2 - b^2. Because this works for every pair of numbers, it gives a quick way to factor any expression of the form (something)^2 - (something else)^2.

Worked Example

Let a = 7 and b = 3. Then a^2 = 49 and b^2 = 9, so a^2 - b^2 = 40. Using the factored form:

(7 + 3)(7 - 3) = 10 × 4 = 40

Both methods agree, confirming the identity.

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)

Does it work with decimals and negatives?
Yes. The identity holds for all real numbers, so \(5.5^2 - 2.5^2\) or \((-4)^2 - 2^2\) are handled correctly.
What if a equals b?
Then \(a^2 - b^2 = 0\), because one of the factors \((a - b)\) becomes 0.
Why is this useful?
It speeds up multiplication (e.g. \(53 \times 47 = 50^2 - 3^2 = 2500 - 9 = 2491\)) and is essential for factoring quadratic expressions.