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Question Number 224833 by fantastic last updated on 06/Oct/25 $$\int\mathrm{sec}\:\theta\:{d}\theta \\ $$ Answered by taha3738 last updated on 06/Oct/25 $$\int\:\mathrm{sec}\:\theta\:{d}\theta\:=\:\int\:\frac{\mathrm{sec}\:\theta\:\left(\mathrm{sec}\:\theta\:+\:\mathrm{tan}\:\theta\right)}{\mathrm{sec}\:\theta\:+\:\mathrm{tan}\:\theta}\:{d}\theta \\ $$$$=\:\int\:\:\frac{\mathrm{sec}^{\mathrm{2}} \theta+\:\mathrm{sec}\:\theta\:\mathrm{tan}\:\theta}{\mathrm{sec}\:\theta\:+\:\mathrm{tan}\:\theta\:}\:{d}\theta\:=\:\mathrm{ln}\:\mid\:\mathrm{sec}\:{x}\:+\:\mathrm{tan}\:{x}\:\mid\:+\:{C} \\ $$$${Because}\:\frac{{d}}{{d}\theta}\:\left(\:\mathrm{sec}\:\theta\:+\:\mathrm{tan}\:\theta\:\right)\:=\:\frac{{d}}{{d}\theta}\:\mathrm{sec}\:\theta\:+\:\frac{{d}}{{d}\theta}\:\mathrm{tan}\:\theta…

Use-the-Gauss-Bonnet-Theorem-to-show-that-the-number-of-holes-in-a-straw-is-1-Then-associate-it-and-show-that-the-Genus-on-the-surface-is-1-

Question Number 224806 by fkwow344 last updated on 05/Oct/25 $$\mathrm{Use}\:\mathrm{the}\:\mathrm{Gauss}\:\mathrm{Bonnet}\:\mathrm{Theorem}\:\mathrm{to}\:\mathrm{show}\:\mathrm{that}\:\mathrm{the} \\ $$$$\mathrm{number}\:\mathrm{of}\:\mathrm{holes}\:\mathrm{in}\:\mathrm{a}\:\mathrm{straw}\:\mathrm{is}\:\mathrm{1}. \\ $$$$\mathrm{Then}\:\mathrm{associate}\:\mathrm{it}\:\mathrm{and}\: \\ $$$$\mathrm{show}\:\mathrm{that}\:\mathrm{the}\:\mathrm{Genus}\:\mathrm{on}\:\mathrm{the}\:\mathrm{surface}\:\mathrm{is}\:\mathrm{1}. \\ $$ Answered by MrAjder last updated on 18/Oct/25…

Question-224807

Question Number 224807 by fantastic last updated on 05/Oct/25 Commented by fantastic last updated on 05/Oct/25 $${It}\:{took}\:{me}\:\mathrm{10}\:{to}\:\mathrm{15}\:{minutes}\:{to}\:{solve} \\ $$$${this}\:{question}.{It}\:{was}\:{not}\:{too}\:{hard} \\ $$$${but}\:{the}\:{question}\:{is}\:{very}\:{interesting} \\ $$$${Here}\:{is}\:{the}\:{question}: \\ $$$${A}\:{bottle}\:{of}\:{syllendrical}\:{shape}…

prove-Sphere-S-R-3-R-x-2-y-2-z-2-R-2-Euler-characteristic-2-by-gauss-Bonnet-theorem-2pi-dA-K-Gauss-curvature-defined-as-K-det-det-I-LN-M-2-EG-F-2-such-that-I-

Question Number 224789 by fkwow344 last updated on 04/Oct/25 $$\mathrm{prove}\:\mathrm{Sphere}\:\mathcal{S};\mathbb{R}^{\mathrm{3}} \rightarrow\mathbb{R} \\ $$$${x}^{\mathrm{2}} +{y}^{\mathrm{2}} +{z}^{\mathrm{2}} ={R}^{\mathrm{2}} \:,\:\mathrm{Euler}\:\mathrm{characteristic}\:\boldsymbol{\chi}=\mathrm{2} \\ $$$$\mathrm{by}\:\mathrm{gauss}-\mathrm{Bonnet}\:\mathrm{theorem} \\ $$$$\mathrm{2}\pi\boldsymbol{\chi}\left(\boldsymbol{\Omega}\right)=\int_{\:\boldsymbol{\Omega}} \:\mathrm{d}{A}\:{K} \\ $$$$\mathrm{Gauss}\:\mathrm{curvature}\:\mathrm{defined}\:\mathrm{as}\:{K}=\frac{\mathrm{det}\:\Pi}{\mathrm{det}\:\mathrm{I}}=\frac{{LN}−{M}^{\mathrm{2}} }{{EG}−{F}^{\mathrm{2}}…

The-value-of-n-for-which-the-divergence-of-the-function-F-r-determinant-r-n-r-xi-yj-zk-determinant-r-0-vanishes-is-a-1-b-1-c-3-d-3-

Question Number 224732 by fantastic last updated on 30/Sep/25 $${The}\:{value}\:{of}\:{n}\:{for}\:{which}\:{the}\:{divergence} \\ $$$${of}\:{the}\:{function} \\ $$$$\mathrm{F}=\frac{\mathrm{r}}{\begin{vmatrix}{\mathrm{r}}\end{vmatrix}^{{n}} },\:\mathrm{r}=\mathrm{x}\hat {\mathrm{i}}+{y}\hat {\mathrm{j}}+{z}\hat {\mathrm{k}},\begin{vmatrix}{\mathrm{r}}\end{vmatrix}\neq\mathrm{0}, \\ $$$${vanishes}\:{is} \\ $$$$\left.{a}\right)\mathrm{1} \\ $$$$\left.{b}\right)−\mathrm{1} \\…

Let-u-y-2-x-2-x-2-y-2-v-z-2-y-2-y-2-z-2-for-x-0-y-0z-0-Let-w-f-u-v-where-f-is-a-real-valued-function-defined-on-R-2-having-continuous-first-order-partial-derivatives-the-value-

Question Number 224735 by fantastic last updated on 30/Sep/25 $${Let}\:{u}=\frac{{y}^{\mathrm{2}} −{x}^{\mathrm{2}} }{{x}^{\mathrm{2}} {y}^{\mathrm{2}} },\:{v}=\frac{{z}^{\mathrm{2}} −{y}^{\mathrm{2}} }{{y}^{\mathrm{2}} {z}^{\mathrm{2}} }\:{for}\:{x}\neq\mathrm{0},{y}\neq\mathrm{0}{z}\neq\mathrm{0}. \\ $$$${Let}\:{w}={f}\left({u},{v}\right),\:{where}\:{f}\:{is}\:{a}\:{real} \\ $$$${valued}\:{function}\:{defined}\:{on}\:{R}^{\mathrm{2}} \\ $$$${having}\:{continuous}\:{first}\:{order} \\…

Let-f-be-a-continuously-differentiable-function-such-that-0-2x-2-f-t-dt-e-cos-x-2-for-all-x-0-the-value-of-f-pi-

Question Number 224733 by fantastic last updated on 30/Sep/25 $${Let}\:{f}\:{be}\:{a}\:{continuously}\:{differentiable}\:{function} \\ $$$${such}\:{that} \\ $$$$\int_{\mathrm{0}} ^{\mathrm{2}{x}^{\mathrm{2}} } {f}\left({t}\right){dt}={e}^{\mathrm{cos}\:{x}^{\mathrm{2}} } \:{for}\:{all}\:{x}\in\left(\mathrm{0},\infty\right) \\ $$$${the}\:{value}\:{of}\:{f}\:'\left(\pi\right)=? \\ $$ Answered by…