隱式微分計算器（附步驟）
逐步計算隱式導數
隱式微分計算器將求出隱式函數的一階與二階導數，可將 $$$y$$$ 視為 $$$x$$$ 的函數，或將 $$$x$$$ 視為 $$$y$$$ 的函數，並顯示步驟。
您的輸入
求$$$\frac{d}{dx} \left(x^{3} + y^{3} = 2 x y\right)$$$。
解答
分別對等式兩邊求導（將 $$$y$$$ 視為 $$$x$$$ 的函數）：$$$\frac{d}{dx} \left(x^{3} + y^{3}{\left(x \right)}\right) = \frac{d}{dx} \left(2 x y{\left(x \right)}\right)$$$。
對等式左邊求導數。
和/差的導數等於導數的和/差：
$${\color{red}\left(\frac{d}{dx} \left(x^{3} + y^{3}{\left(x \right)}\right)\right)} = {\color{red}\left(\frac{d}{dx} \left(x^{3}\right) + \frac{d}{dx} \left(y^{3}{\left(x \right)}\right)\right)}$$套用冪次法則 $$$\frac{d}{dx} \left(x^{n}\right) = n x^{n - 1}$$$，取 $$$n = 3$$$：
$${\color{red}\left(\frac{d}{dx} \left(x^{3}\right)\right)} + \frac{d}{dx} \left(y^{3}{\left(x \right)}\right) = {\color{red}\left(3 x^{2}\right)} + \frac{d}{dx} \left(y^{3}{\left(x \right)}\right)$$函數 $$$y^{3}{\left(x \right)}$$$ 是兩個函數 $$$f{\left(u \right)} = u^{3}$$$ 與 $$$g{\left(x \right)} = y{\left(x \right)}$$$ 之複合 $$$f{\left(g{\left(x \right)} \right)}$$$。
應用鏈式法則 $$$\frac{d}{dx} \left(f{\left(g{\left(x \right)} \right)}\right) = \frac{d}{du} \left(f{\left(u \right)}\right) \frac{d}{dx} \left(g{\left(x \right)}\right)$$$：
$$3 x^{2} + {\color{red}\left(\frac{d}{dx} \left(y^{3}{\left(x \right)}\right)\right)} = 3 x^{2} + {\color{red}\left(\frac{d}{du} \left(u^{3}\right) \frac{d}{dx} \left(y{\left(x \right)}\right)\right)}$$套用冪次法則 $$$\frac{d}{du} \left(u^{n}\right) = n u^{n - 1}$$$，取 $$$n = 3$$$：
$$3 x^{2} + {\color{red}\left(\frac{d}{du} \left(u^{3}\right)\right)} \frac{d}{dx} \left(y{\left(x \right)}\right) = 3 x^{2} + {\color{red}\left(3 u^{2}\right)} \frac{d}{dx} \left(y{\left(x \right)}\right)$$返回原變數：
$$3 x^{2} + 3 {\color{red}\left(u\right)}^{2} \frac{d}{dx} \left(y{\left(x \right)}\right) = 3 x^{2} + 3 {\color{red}\left(y{\left(x \right)}\right)}^{2} \frac{d}{dx} \left(y{\left(x \right)}\right)$$因此，$$$\frac{d}{dx} \left(x^{3} + y^{3}{\left(x \right)}\right) = 3 x^{2} + 3 y^{2}{\left(x \right)} \frac{d}{dx} \left(y{\left(x \right)}\right)$$$。
對等式右邊求導。
套用常數倍法則 $$$\frac{d}{dx} \left(c f{\left(x \right)}\right) = c \frac{d}{dx} \left(f{\left(x \right)}\right)$$$，使用 $$$c = 2$$$ 與 $$$f{\left(x \right)} = x y{\left(x \right)}$$$：
$${\color{red}\left(\frac{d}{dx} \left(2 x y{\left(x \right)}\right)\right)} = {\color{red}\left(2 \frac{d}{dx} \left(x y{\left(x \right)}\right)\right)}$$將乘積法則 $$$\frac{d}{dx} \left(f{\left(x \right)} g{\left(x \right)}\right) = \frac{d}{dx} \left(f{\left(x \right)}\right) g{\left(x \right)} + f{\left(x \right)} \frac{d}{dx} \left(g{\left(x \right)}\right)$$$ 應用於 $$$f{\left(x \right)} = x$$$ 和 $$$g{\left(x \right)} = y{\left(x \right)}$$$：
$$2 {\color{red}\left(\frac{d}{dx} \left(x y{\left(x \right)}\right)\right)} = 2 {\color{red}\left(\frac{d}{dx} \left(x\right) y{\left(x \right)} + x \frac{d}{dx} \left(y{\left(x \right)}\right)\right)}$$套用冪次法則 $$$\frac{d}{dx} \left(x^{n}\right) = n x^{n - 1}$$$，取 $$$n = 1$$$，也就是 $$$\frac{d}{dx} \left(x\right) = 1$$$：
$$2 x \frac{d}{dx} \left(y{\left(x \right)}\right) + 2 y{\left(x \right)} {\color{red}\left(\frac{d}{dx} \left(x\right)\right)} = 2 x \frac{d}{dx} \left(y{\left(x \right)}\right) + 2 y{\left(x \right)} {\color{red}\left(1\right)}$$因此，$$$\frac{d}{dx} \left(2 x y{\left(x \right)}\right) = 2 x \frac{d}{dx} \left(y{\left(x \right)}\right) + 2 y{\left(x \right)}$$$。
因此，我們得到以下關於導數的線性方程：$$$3 x^{2} + 3 y^{2} \frac{dy}{dx} = 2 x \frac{dy}{dx} + 2 y$$$。
解得 $$$\frac{dy}{dx} = \frac{3 x^{2} - 2 y}{2 x - 3 y^{2}}$$$。
答案
$$$\frac{dy}{dx} = \frac{3 x^{2} - 2 y}{2 x - 3 y^{2}}$$$A