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Category: Differentiation

Question-137650

Question Number 137650 by bemath last updated on 05/Apr/21 Answered by bemath last updated on 05/Apr/21 $${By}\:{Langrange}\:{multiplier} \\ $$$${f}\left({x},{y},\lambda\right)=\:{x}^{\mathrm{2}} +{y}^{\mathrm{2}} +\lambda\left(\mathrm{6}{x}^{\mathrm{2}} +\mathrm{2}{xy}+\mathrm{6}{y}^{\mathrm{2}} −\mathrm{9}\right) \\ $$$$\frac{\partial{f}}{\partial{x}}\:=\:\mathrm{2}{x}+\lambda\left(\mathrm{12}{x}+\mathrm{2}{y}\right)=\mathrm{0}…

y-ln-3x-2-x-solve-y-6-x-

Question Number 72044 by 20190927 last updated on 23/Oct/19 $$\mathrm{y}=\mathrm{ln}\left(\mathrm{3x}^{\mathrm{2}} +\mathrm{x}\right)\:\:\:\mathrm{solve}\:\mathrm{y}^{\left(\mathrm{6}\right)} \left(\mathrm{x}\right) \\ $$ Commented by mathmax by abdo last updated on 24/Oct/19 $${we}\:{have}\:{y}^{'} \left({x}\right)=\frac{\mathrm{6}{x}+\mathrm{1}}{\mathrm{3}{x}^{\mathrm{2}}…

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}? \\…