Menu Close

Category: Differentiation

show-that-if-f-is-a-differentiable-function-at-the-point-x-a-then-f-is-continuous-at-x-a-

Question Number 71769 by psyche last updated on 19/Oct/19 $${show}\:{that}\:{if}\:{f}\:{is}\:{a}\:{differentiable}\:{function}\:{at}\:{the}\:{point}\:{x}={a},\:{then}\:{f}\:{is}\:{continuous}\:{at}\:{x}={a}. \\ $$ Commented by kaivan.ahmadi last updated on 19/Oct/19 $${if}\:{lim}_{{x}\rightarrow{a}} {f}\left({x}\right)\neq{f}\left({a}\right)\:\Rightarrow{lim}_{{x}\rightarrow{a}} {f}\left({x}\right)−{f}\left({a}\right)\neq\mathrm{0}\Rightarrow \\ $$$${then}\:{f}'\left({a}\right)={lim}_{{x}\rightarrow{a}} \frac{{f}\left({x}\right)−{f}\left({a}\right)}{{x}−{a}}=+\infty\vee−\infty…

from-the-figure-above-the-square-S-s-diameter-length-is-increasing-by-25-m-s-to-the-north-east-initially-at-length-30-2-m-and-circle-C-s-radius-is-decreasing-by-2-m-s-initially-at-length-100-m-kn

Question Number 137303 by Raxreedoroid last updated on 31/Mar/21 $$\mathrm{from}\:\mathrm{the}\:\mathrm{figure}\:\mathrm{above} \\ $$$${the}\:{square}\:{S}'\mathrm{s}\:\mathrm{diameter}\:\mathrm{length}\:\mathrm{is}\:\mathrm{increasing} \\ $$$$\mathrm{by}\:\mathrm{25}\:\mathrm{m}/\mathrm{s}\:\mathrm{to}\:\mathrm{the}\:\mathrm{north}−\mathrm{east}\:\mathrm{initially}\:\mathrm{at}\:\mathrm{length}\:\mathrm{30}\sqrt{\mathrm{2}\:}\mathrm{m}\:\mathrm{and}\:\mathrm{circle}\: \\ $$$${C}'\mathrm{s}\:\mathrm{radius}\:\mathrm{is}\:\mathrm{decreasing}\:\mathrm{by}\:\mathrm{2}\:\mathrm{m}/\mathrm{s}\:\mathrm{initially}\:\mathrm{at}\:\mathrm{length}\:\mathrm{100}\:\mathrm{m} \\ $$$$\mathrm{knowing}\:\mathrm{that}\:\mathrm{the}\:\mathrm{blue}\:\mathrm{line}'\mathrm{s}\:\mathrm{length}\:=\:\mathrm{40m} \\ $$$$\mathrm{at}\:\mathrm{what}\:\mathrm{time}\:\mathrm{the}\:\mathrm{horizontal}\:\mathrm{distance}\:\mathrm{between}\:\mathrm{point}\:{p} \\ $$$$\mathrm{and}\:\mathrm{point}\:{q}\:\mathrm{will}\:\mathrm{equal}\:\mathrm{0}? \\ $$$$\mathrm{and}\:\mathrm{what}\:\mathrm{will}\:\mathrm{be}\:\mathrm{the}\:\mathrm{vertical}\:\mathrm{distance}\:\mathrm{at}\:\mathrm{that}\:\mathrm{time}? \\…

complex-analysis-if-f-n-x-d-n-dx-n-x-x-C-C-0-n-C-Z-0-and-g-n-x-0-1-f-n-x-d-then-find-the-value-of-

Question Number 137275 by mnjuly1970 last updated on 31/Mar/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:……{complex}\:\:{analysis}….. \\ $$$$\:\:\:\:{if}\:,\:\:{f}\left(\alpha,{n},{x}\right)=\frac{{d}^{\:{n}} }{{dx}^{{n}} }\left(\alpha^{{x}} \right)\:\:,\:{x}\in\mathbb{C} \\ $$$$\:\:\:\:\:\alpha\in\mathbb{C}−\left\{\mathrm{0}\right\}\:,\:{n}\in\mathbb{C}−\mathbb{Z}^{−} \cup\left\{\mathrm{0}\right\} \\ $$$$\:\:\:\:\:{and}\:\:{g}\left({n},{x}\right)=\int_{\mathrm{0}} ^{\:\mathrm{1}} {f}\left(\alpha,{n},{x}\right){d}\alpha \\ $$$$\:\:\:\:\:{then}\:\:{find}\:\:{the}\:{value}\:{of}\:… \\…

3sin-x-2-2sin-x-3-2-dx-

Question Number 137249 by bemath last updated on 31/Mar/21 $$\int\:\frac{\left(\mathrm{3sin}\:\mathrm{x}+\mathrm{2}\right)}{\left(\mathrm{2sin}\:\mathrm{x}+\mathrm{3}\right)^{\mathrm{2}} }\:\mathrm{dx}\:=? \\ $$ Answered by bemath last updated on 31/Mar/21 $$\mathrm{let}\:\mathrm{tan}\:\left(\frac{\mathrm{x}}{\mathrm{2}}\right)=\mathrm{u}\: \begin{cases}{\mathrm{dx}=\frac{\mathrm{2}}{\mathrm{u}^{\mathrm{2}} +\mathrm{1}}\:\mathrm{du}}\\{\mathrm{sin}\:\mathrm{x}=\frac{\mathrm{2u}}{\mathrm{u}^{\mathrm{2}} +\mathrm{1}}}\end{cases} \\…

Question-137226

Question Number 137226 by SLVR last updated on 31/Mar/21 Answered by MJS_new last updated on 31/Mar/21 $${f}\left({x}\right)=\mathrm{2ln}\:{x} \\ $$$${x}^{\mathrm{3}} −\mathrm{6}{x}^{\mathrm{2}} +\mathrm{11}{x}−\mathrm{6}=\left({x}−\mathrm{1}\right)\left({x}−\mathrm{2}\right)\left({x}−\mathrm{3}\right) \\ $$$$\mathrm{the}\:\mathrm{curves}\:\mathrm{intersect}\:\mathrm{at}\:{x}=\mathrm{1} \\ $$$$\underset{\mathrm{0}}…

advanced-calculus-prove-that-0-1-ln-ln-1-x-dx-ln-1-x-pi-ln-4-

Question Number 137190 by mnjuly1970 last updated on 30/Mar/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:….{advanced}\:…….\:\:{calculus}….. \\ $$$$\:\:\:\:\:\:\:\:{prove}\:{that}::: \\ $$$$\boldsymbol{\phi}=\int_{\mathrm{0}} ^{\:\mathrm{1}} {ln}\left({ln}\left(\frac{\mathrm{1}}{{x}}\right)\right).\frac{{dx}}{\:\sqrt{{ln}\left(\frac{\mathrm{1}}{{x}}\right)}}\:=−\sqrt{\pi}\:\left(\gamma+{ln}\left(\mathrm{4}\right)\right) \\ $$$$ \\ $$ Answered by Dwaipayan Shikari last…