> [!summary] This proof uses the definition of a limit to prove the constant multiple rule. > **Key Result:** $\frac{d}{dx}[C\cdot F(x)] = C\cdot F'(x)$ >[!info]+ Read Time **⏱ 1 min** # Mathematical Proof > [!warning] Assumptions To prove the derivative of a constant and a function using [[Direct Proof|direct proof]] assume the following: > - The definition of a [[Derivative|derivative]] is $\frac{dy}{dx} = f'(x) = \displaystyle \lim_{ h \to 0 } \frac{f(x+h)-f(x)}{h}$ Prove that $\frac{d}{dx}[C\cdot F(x)] = C\cdot F'(x)$ $ \begin{align*} \frac{d}{dx}[C\cdot F(x)] &= \displaystyle \lim_{ h \to 0 } \frac{C \cdot f(x+h)- C\cdot f(x)}{h} \\ &=\displaystyle C \cdot\lim_{ h \to 0 } \frac{ f(x+h)- \cdot f(x)}{h} \\ &= C \cdot F'(x) \end{align*} $ --- <!-- Light Mode Newsletter Embed --> <div class="mm-form-light"> <iframe src="https://updates.cyberleadhub.com/widget/form/Y0kpQVpjJQuxEfX59m17" id="inline-Y0kpQVpjJQuxEfX59m17" title="Join Math & Matter Newsletter (Light)" data-height="900" scrolling="no" allowtransparency="true" loading="lazy" style="width:100%;height:350px;border:none;border-radius:10px;background:transparent;overflow:hidden" ></iframe> </div> <!-- Dark Mode Newsletter Embed --> <div class="mm-form-dark"> <iframe src="https://updates.cyberleadhub.com/widget/form/lbeDLm24VjuaFxhjccA1" id="inline-lbeDLm24VjuaFxhjccA1" title="Join Math & Matter Newsletter (Dark)" data-height="900" scrolling="no" allowtransparency="true" loading="lazy" style="width:100%;height:350px;border:none;border-radius:10px;background:transparent;overflow:hidden" ></iframe> </div> <!-- Provider script (only once) --> <script src="https://updates.cyberleadhub.com/js/form_embed.js"></script>