Question Number 91099 by Angnysr11 last updated on 28/Apr/20
Commented by Angnysr11 last updated on 28/Apr/20
$${i}\begin{vmatrix}{\begin{bmatrix}{{i}\:{can}'{t}\:{solve}\:{this}…\:{please}\:{help}}\\{}\end{bmatrix}}\\{}\end{vmatrix} \\ $$
Commented by john santu last updated on 28/Apr/20
$$\left.\mathrm{15}\right)\:\underset{\mathrm{4}} {\overset{\mathrm{8}} {\int}}\:\mathrm{5}{u}\sqrt{\mathrm{4}+\mathrm{2}{u}}\:{du}\:= \\ $$$$\sqrt{\mathrm{4}+\mathrm{2}{u}}\:=\:{w}\:\Rightarrow\:\mathrm{2}{du}\:=\:\mathrm{2}{w}\:{dw}\: \\ $$$$\underset{\mathrm{2}\sqrt{\mathrm{3}}} {\int}^{\mathrm{2}\sqrt{\mathrm{5}}} \mathrm{5}\left(\frac{{w}^{\mathrm{2}} −\mathrm{4}}{\mathrm{2}}\right).{w}\:{wdw}\:=\: \\ $$$$\frac{\mathrm{5}}{\mathrm{2}}\int_{\mathrm{2}\sqrt{\mathrm{3}}} ^{\mathrm{2}\sqrt{\mathrm{5}}} \left({w}^{\mathrm{4}} −\mathrm{4}{w}^{\mathrm{2}} \right){dw}\:= \\ $$$$\frac{\mathrm{5}}{\mathrm{2}}\left[\frac{\mathrm{1}}{\mathrm{5}}{w}^{\mathrm{5}} −\frac{\mathrm{4}}{\mathrm{3}}{w}^{\mathrm{3}} \:\right]_{\mathrm{2}\sqrt{\mathrm{3}}} ^{\mathrm{2}\sqrt{\mathrm{5}}} \\ $$$${now}\:{it}\:{easy}\:\:{to}\:{solve} \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{2}\right)\:\int\:\mathrm{10}{x}\left(\mathrm{5}{x}+\mathrm{3}\right)^{\mathrm{3}} \:{dx}\:=\mathrm{10}\:.\mathrm{5}^{\mathrm{3}} \:\int{x}\left({x}+\frac{\mathrm{3}}{\mathrm{5}}\right)^{\mathrm{3}} \:{dx} \\ $$$$=_{{by}\:{parts}} \:\:\mathrm{10}.\mathrm{5}^{\mathrm{3}} \left\{\:\:\frac{{x}}{\mathrm{4}}\left({x}+\frac{\mathrm{3}}{\mathrm{5}}\right)^{\mathrm{4}} −\int\:\:\frac{\mathrm{1}}{\mathrm{4}}\left({x}+\frac{\mathrm{3}}{\mathrm{5}}\right)^{\mathrm{4}} \:{dx}\right\} \\ $$$$=\mathrm{20}.\mathrm{5}^{\mathrm{3}} \left\{\:\frac{{x}}{\mathrm{4}}\left({x}+\frac{\mathrm{3}}{\mathrm{5}}\right)^{\mathrm{4}} −\frac{\mathrm{1}}{\mathrm{20}}\:\left({x}+\frac{\mathrm{3}}{\mathrm{5}}\right)^{\mathrm{5}} \right\}\:+{C} \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{1}\right)\:{by}\:{parts}\:\:\int\:{x}\left({x}−\mathrm{2}\right)^{\mathrm{4}} \:{dx}\:=\frac{{x}\left({x}−\mathrm{2}\right)^{\mathrm{5}} }{\mathrm{5}} \\ $$$$−\int\frac{\left({x}−\mathrm{2}\right)^{\mathrm{5}} }{\mathrm{5}}{dx}\:=\frac{{x}\left({x}−\mathrm{2}\right)^{\mathrm{5}} }{\mathrm{5}}−\frac{\mathrm{1}}{\mathrm{30}}\left({x}−\mathrm{2}\right)^{\mathrm{6}} \:+{C} \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{3}\right)\:\int_{\mathrm{2}} ^{\mathrm{5}} {x}\sqrt{{x}+\mathrm{3}}{dx}\:\:=_{\sqrt{{x}+\mathrm{3}}={t}} \:\:\int_{\sqrt{\mathrm{5}}} ^{\mathrm{2}\sqrt{\mathrm{2}}} \left({t}^{\mathrm{2}} −\mathrm{3}\right){t}\:\left(\mathrm{2}{t}\right){dt} \\ $$$$=\mathrm{2}\:\int_{\sqrt{\mathrm{5}}} ^{\mathrm{2}\sqrt{\mathrm{2}}} \left({t}^{\mathrm{4}} −\mathrm{3}{t}^{\mathrm{2}} \right){dt}\:=\mathrm{2}\left[\frac{{t}^{\mathrm{5}} }{\mathrm{5}}−{t}^{\mathrm{3}} \right]_{\sqrt{\mathrm{5}}} ^{\mathrm{2}\sqrt{\mathrm{2}}} \\ $$$$=\mathrm{2}\left(\frac{\left(\mathrm{2}\sqrt{\mathrm{2}}\right)^{\mathrm{5}} }{\mathrm{5}}−\left(\mathrm{2}\sqrt{\mathrm{2}}\right)^{\mathrm{3}} −\frac{\left(\sqrt{\mathrm{5}}\right)^{\mathrm{5}} }{\mathrm{5}}\:+\left(\sqrt{\mathrm{5}}\right)^{\mathrm{3}} \right) \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{4}\right)\:\int_{\mathrm{1}} ^{\mathrm{3}} \:\mathrm{3}{x}^{\mathrm{2}} \sqrt{{x}+\mathrm{7}}{dx}\:=_{.\sqrt{{x}+\mathrm{7}}={t}} \:\:\int_{\mathrm{2}\sqrt{\mathrm{2}}} ^{\sqrt{\mathrm{10}}} \mathrm{3}\left({t}^{\mathrm{2}} −\mathrm{7}\right)^{\mathrm{2}} {t}\left(\mathrm{2}{t}\right){dt} \\ $$$$=\mathrm{6}\:\int_{\mathrm{2}\sqrt{\mathrm{2}}} ^{\sqrt{\mathrm{10}}} {t}^{\mathrm{2}} \left({t}^{\mathrm{4}} −\mathrm{14}{t}^{\mathrm{2}} +\mathrm{49}\right){dt} \\ $$$$=\mathrm{6}\:\int_{\mathrm{2}\sqrt{\mathrm{2}}} ^{\sqrt{\mathrm{10}}} \left({t}^{\mathrm{6}} −\mathrm{14}{t}^{\mathrm{4}} \:+\mathrm{49}{t}^{\mathrm{2}} \right){dt} \\ $$$$=\mathrm{6}\left[\frac{{t}^{\mathrm{7}} }{\mathrm{7}}−\frac{\mathrm{14}}{\mathrm{5}}{t}^{\mathrm{5}} \:+\frac{\mathrm{49}}{\mathrm{3}}{t}^{\mathrm{3}} \right]_{\mathrm{2}\sqrt{\mathrm{2}}} ^{\sqrt{\mathrm{10}}} \\ $$$$=\mathrm{6}\left(\:\frac{\left(\sqrt{\mathrm{10}}\right)^{\mathrm{7}} }{\mathrm{7}}−\frac{\mathrm{14}}{\mathrm{5}}\left(\sqrt{\mathrm{10}}\right)^{\mathrm{5}} \:+\frac{\mathrm{49}}{\mathrm{3}}\left(\sqrt{\mathrm{10}}\right)^{\mathrm{3}} −\frac{\left(\mathrm{2}\sqrt{\mathrm{2}}\right)^{\mathrm{7}} }{\mathrm{7}}+\frac{\mathrm{14}}{\mathrm{5}}\left(\mathrm{2}\sqrt{\mathrm{2}}\right)^{\mathrm{5}} \right. \\ $$$$\left.−\frac{\mathrm{49}}{\mathrm{3}}\left(\mathrm{2}\sqrt{\mathrm{2}}\right)^{\mathrm{3}} \right) \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{10}\right)\:\int\:{x}^{\mathrm{2}} \left(^{\mathrm{3}} \sqrt{{x}+\mathrm{1}}\right){dx}\:\:{we}\:{do}\:{the}\:{changement}\:^{\mathrm{3}} \sqrt{{x}+\mathrm{1}}={t} \\ $$$${x}+\mathrm{1}\:={t}^{\mathrm{3}} \:\Rightarrow\:{I}\:=\int\:\left({t}^{\mathrm{3}} −\mathrm{1}\right)^{\mathrm{2}} {t}\:\left(\mathrm{3}{t}^{\mathrm{2}} \right){dt} \\ $$$$=\mathrm{3}\:\int\:{t}^{\mathrm{3}} \left({t}^{\mathrm{6}} −\mathrm{2}{t}^{\mathrm{3}} +\mathrm{1}\right){dt} \\ $$$$=\mathrm{3}\int\:\left({t}^{\mathrm{9}} −\mathrm{2}{t}^{\mathrm{6}} \:+{t}^{\mathrm{3}} \right){dt}\:=\mathrm{3}\left(\frac{{t}^{\mathrm{10}} }{\mathrm{10}}−\frac{\mathrm{2}}{\mathrm{7}}{t}^{\mathrm{7}} \:+\frac{{t}^{\mathrm{4}} }{\mathrm{4}}\right)\:+{C} \\ $$$$=\frac{\mathrm{3}}{\mathrm{10}}{t}^{\mathrm{10}} \:−\frac{\mathrm{6}}{\mathrm{7}}{t}^{\mathrm{7}} \:+\frac{\mathrm{3}}{\mathrm{4}}\:{t}^{\mathrm{4}} \:+{C} \\ $$$$=\frac{\mathrm{3}}{\mathrm{10}}\left(^{\mathrm{3}} \sqrt{{x}+\mathrm{1}}\right)^{\mathrm{10}} \:−\frac{\mathrm{6}}{\mathrm{7}}\left(^{\mathrm{3}} \sqrt{{x}+\mathrm{1}}\right)^{\mathrm{7}} \:+\frac{\mathrm{3}}{\mathrm{4}}\left(^{\mathrm{3}} \sqrt{{x}+\mathrm{1}}\right)^{\mathrm{4}\:} \:+{C} \\ $$$$ \\ $$$$ \\ $$$$ \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{11}\right)\:\int\:\:\frac{{x}}{\:\sqrt{{x}+\mathrm{2}}}{dx}\:{we}\:{do}\:{the}\:{changement}\:\sqrt{{x}+\mathrm{2}}={t}\:\Rightarrow \\ $$$$\int\:\:\frac{{x}}{\:\sqrt{{x}+\mathrm{2}}}{dx}\:=\int\:\:\frac{{t}^{\mathrm{2}} −\mathrm{2}}{{t}}\left(\mathrm{2}{t}\right){dt} \\ $$$$=\mathrm{2}\:\int\left({t}^{\mathrm{2}} −\mathrm{2}\right){dt}\:=\mathrm{2}\left(\frac{{t}^{\mathrm{3}} }{\mathrm{3}}−\mathrm{2}{t}\right)\:+{C} \\ $$$$=\frac{\mathrm{2}}{\mathrm{3}}{t}^{\mathrm{3}} −\mathrm{4}{t}\:+{C} \\ $$$$=\frac{\mathrm{2}}{\mathrm{3}}\left(\sqrt{{x}+\mathrm{2}}\right)^{\mathrm{3}} −\mathrm{4}\sqrt{{x}+\mathrm{2}}\:+{C} \\ $$
Commented by abdomathmax last updated on 28/Apr/20
$$\left.\mathrm{12}\right)\:\int\:{x}^{\mathrm{2}} \sqrt{\mathrm{4}−{x}}{dx}\:{we}\:{do}\:{the}\:{changement}\:\sqrt{\mathrm{4}−{x}}={u}\:\Rightarrow \\ $$$$\mathrm{4}−{x}\:={u}^{\mathrm{2}} \:\Rightarrow{x}\:=\mathrm{4}−{u}^{\mathrm{2}} \:\Rightarrow \\ $$$$\int\:{x}^{\mathrm{2}} \sqrt{\mathrm{4}−{x}}{dx}\:=\int\:\left(\mathrm{4}−{u}^{\mathrm{2}} \right)^{\mathrm{2}} {u}\:\left(−\mathrm{2}{u}\right){du} \\ $$$$=−\mathrm{2}\int\:{u}^{\mathrm{2}} \left({u}^{\mathrm{4}} +\mathrm{8}{u}^{\mathrm{2}} \:+\mathrm{16}\right){du} \\ $$$$=−\mathrm{2}\int\:\left({u}^{\mathrm{6}} \:+\mathrm{8}{u}^{\mathrm{4}} \:+\mathrm{16}{u}^{\mathrm{2}} \right){du} \\ $$$$=−\mathrm{2}\left(\:\frac{{u}^{\mathrm{7}} }{\mathrm{7}}\:+\frac{\mathrm{8}}{\mathrm{5}}{u}^{\mathrm{5}} \:+\frac{\mathrm{16}}{\mathrm{3}}{u}^{\mathrm{2}} \right)\:+{C} \\ $$$$=−\frac{\mathrm{2}}{\mathrm{7}}\left(\sqrt{\mathrm{4}−{x}}\right)^{\mathrm{7}} −\frac{\mathrm{16}}{\mathrm{5}}\left(\sqrt{\mathrm{4}−{x}}\right)^{\mathrm{5}} \:−\frac{\mathrm{32}}{\mathrm{3}}\left(\sqrt{\mathrm{4}−{x}}\right)^{\mathrm{2}} \:+{C} \\ $$
Commented by mathmax by abdo last updated on 28/Apr/20
$$\left.\mathrm{13}\right)\:\int_{\mathrm{1}} ^{\mathrm{4}} {x}\left({x}+\mathrm{5}\right)^{\mathrm{3}} {dx}\:=_{{by}\:{parts}} \:\:\left[\frac{{x}}{\mathrm{4}}\left({x}+\mathrm{5}\right)^{\mathrm{4}} \right]_{\mathrm{1}} ^{\mathrm{4}} −\int_{\mathrm{1}} ^{\mathrm{4}} \frac{\mathrm{1}}{\mathrm{4}}\left({x}+\mathrm{5}\right)^{\mathrm{4}} \:{dx} \\ $$$$=\mathrm{9}^{\mathrm{4}} −\frac{\mathrm{6}^{\mathrm{4}} }{\mathrm{4}}−\frac{\mathrm{1}}{\mathrm{20}}\left[\left({x}+\mathrm{5}\right)^{\mathrm{5}} \right]_{\mathrm{1}} ^{\mathrm{4}} \:=\mathrm{9}^{\mathrm{4}} −\frac{\mathrm{6}^{\mathrm{4}} }{\mathrm{4}}−\frac{\mathrm{1}}{\mathrm{20}}\left(\:\mathrm{9}^{\mathrm{5}} −\mathrm{6}^{\mathrm{5}} \right) \\ $$
Commented by mathmax by abdo last updated on 28/Apr/20
$$\left.\mathrm{18}\right)\:\:{I}\:=\int\:\left({x}+\mathrm{1}\right)\left({x}+\mathrm{5}\right)^{−\mathrm{3}} \:{dx}\:\:{by}\:{parts}\:{u}\:={x}+\mathrm{1}\:{and}\:{v}^{'} =\left({x}+\mathrm{5}\right)^{−\mathrm{3}} \\ $$$${I}\:=\frac{\mathrm{1}}{−\mathrm{2}}\left({x}+\mathrm{1}\right)\left({x}+\mathrm{5}\right)^{−\mathrm{2}} \:+\frac{\mathrm{1}}{\mathrm{2}}\int\:\:\left({x}+\mathrm{5}\right)^{−\mathrm{2}} \:{dx} \\ $$$$=−\frac{\left({x}+\mathrm{1}\right)}{\mathrm{2}\left({x}+\mathrm{5}\right)^{\mathrm{2}} }\:+\frac{\mathrm{1}}{\mathrm{2}}\int\:\:\frac{{dx}}{\left({x}+\mathrm{5}\right)^{\mathrm{2}} }\:=−\frac{{x}+\mathrm{1}}{\mathrm{2}\left({x}+\mathrm{5}\right)^{\mathrm{2}} }−\frac{\mathrm{1}}{\mathrm{2}\left({x}+\mathrm{5}\right)}\:+{C} \\ $$
Commented by mathmax by abdo last updated on 28/Apr/20
$$\left.\mathrm{15}\right)\:{I}\:=\int_{\mathrm{4}} ^{\mathrm{8}} \:\mathrm{5}{x}\sqrt{\mathrm{4}+\mathrm{2}{x}}{dx}\:\:{we}\:{do}\:{the}\:{changement}\:\sqrt{\mathrm{4}+\mathrm{2}{x}}={t}\:\Rightarrow \\ $$$$\mathrm{4}+\mathrm{2}{x}\:={t}^{\mathrm{2}} \:\Rightarrow\mathrm{2}{x}\:={t}^{\mathrm{2}} −\mathrm{4}\:\Rightarrow{x}\:=\frac{{t}^{\mathrm{2}} }{\mathrm{2}}−\mathrm{2}\:\Rightarrow \\ $$$${I}\:=\mathrm{5}\:\int_{\mathrm{2}\sqrt{\mathrm{3}}} ^{\mathrm{2}\sqrt{\mathrm{5}}} \:\:\left(\frac{{t}^{\mathrm{2}} }{\mathrm{2}}−\mathrm{2}\right){t}\:\left({t}\right){dt}\:=\mathrm{5}\:\int_{\mathrm{2}\sqrt{\mathrm{3}}} ^{\mathrm{2}\sqrt{\mathrm{5}}} \left(\frac{{t}^{\mathrm{4}} }{\mathrm{2}}−\mathrm{2}{t}^{\mathrm{2}} \right){dt} \\ $$$$=\mathrm{5}\left[\frac{\mathrm{1}}{\mathrm{10}}{t}^{\mathrm{5}} −\frac{\mathrm{2}}{\mathrm{3}}{t}^{\mathrm{3}} \right]_{\mathrm{2}\sqrt{\mathrm{3}}} ^{\mathrm{2}\sqrt{\mathrm{5}}} \:\:=\mathrm{5}\left(\:\:\frac{\left(\mathrm{2}\sqrt{\mathrm{5}}\right)^{\mathrm{5}} }{\mathrm{10}}−\frac{\mathrm{2}}{\mathrm{3}}\left(\mathrm{2}\sqrt{\mathrm{5}}\right)^{\mathrm{3}} −\frac{\left(\mathrm{2}\sqrt{\mathrm{3}}\right)^{\mathrm{5}} }{\mathrm{10}}+\frac{\mathrm{2}}{\mathrm{3}}\left(\mathrm{2}\sqrt{\mathrm{3}}\right)^{\mathrm{3}} \right) \\ $$
Answered by Kunal12588 last updated on 28/Apr/20
$$\mathrm{1}.\:\int{u}\left({u}−\mathrm{2}\right)^{\mathrm{4}} {du}=\int\left({u}−\mathrm{2}\right)^{\mathrm{5}} {du}+\mathrm{2}\int\left({u}−\mathrm{2}\right)^{\mathrm{4}} {du} \\ $$$$\:\:\:\:\:\:\:=\:\frac{\mathrm{1}}{\mathrm{6}}\left({u}−\mathrm{2}\right)^{\mathrm{6}} +\frac{\mathrm{2}}{\mathrm{5}}\left({u}−\mathrm{2}\right)^{\mathrm{5}} +{C} \\ $$$$\mathrm{2}.\:\int\mathrm{10}{u}\left(\mathrm{5}{u}+\mathrm{3}\right)^{\mathrm{3}} {du}=\mathrm{2}\int\left(\mathrm{5}{u}+\mathrm{3}\right)^{\mathrm{4}} {du}−\mathrm{6}\int\left(\mathrm{5}{u}+\mathrm{3}\right)^{\mathrm{3}} {du}\: \\ $$$$\:\:\:\:\:\:\:=\frac{\mathrm{2}}{\mathrm{25}}\left(\mathrm{5}{u}+\mathrm{3}\right)^{\mathrm{5}} −\frac{\mathrm{3}}{\mathrm{10}}\left(\mathrm{5}{u}+\mathrm{3}\right)^{\mathrm{4}} +{C} \\ $$$$\mathrm{3}.\:\int_{\mathrm{2}} ^{\mathrm{5}} {u}\sqrt{{u}+\mathrm{3}}\:{du}=\int_{\mathrm{2}} ^{\mathrm{5}} \left({u}+\mathrm{3}\right)^{\mathrm{3}/\mathrm{2}} {du}−\mathrm{3}\int_{\mathrm{2}} ^{\mathrm{5}} \left({u}+\mathrm{3}\right)^{\mathrm{1}/\mathrm{2}} {du} \\ $$$$\:\:\:\:\:\:\:=\frac{\mathrm{2}}{\mathrm{5}}\left[\left({u}+\mathrm{3}\right)^{\mathrm{2}} \sqrt{{u}+\mathrm{3}}\right]_{\mathrm{2}} ^{\mathrm{5}} −\mathrm{2}\left[\left({u}+\mathrm{3}\right)\sqrt{{u}+\mathrm{3}}\right]_{\mathrm{2}} ^{\mathrm{5}} \\ $$$$\:\:\:\:\:\:\:=\frac{\mathrm{2}}{\mathrm{5}}\left(\mathrm{128}\sqrt{\mathrm{2}}−\mathrm{25}\sqrt{\mathrm{5}}\right)−\mathrm{2}\left(\mathrm{16}\sqrt{\mathrm{2}}−\mathrm{5}\sqrt{\mathrm{5}}\right) \\ $$$$\:\:\:\:\:\:\:=\frac{\mathrm{96}\sqrt{\mathrm{2}}}{\mathrm{5}} \\ $$$$\mathrm{4}.\:\int_{\mathrm{1}} ^{\mathrm{3}} \mathrm{3}{u}^{\mathrm{2}} \sqrt{{u}+\mathrm{7}}\:{du}=\int_{\mathrm{1}} ^{\mathrm{3}} \mathrm{3}\left(\left({u}+\mathrm{7}\right)−\mathrm{7}\right)^{\mathrm{2}} \sqrt{{u}+\mathrm{7}}\:{du} \\ $$$$=\mathrm{3}\left[\int_{\mathrm{1}} ^{\mathrm{3}} \left({u}+\mathrm{7}\right)^{\mathrm{5}/\mathrm{2}} {du}−\mathrm{14}\int_{\mathrm{1}} ^{\mathrm{3}} \left({u}+\mathrm{7}\right)^{\mathrm{3}/\mathrm{2}} {du}+\mathrm{49}\int\left({u}+\mathrm{7}\right)^{\mathrm{1}/\mathrm{2}} {du}\right] \\ $$$$=\frac{\mathrm{6}}{\mathrm{7}}\left[\left({u}+\mathrm{7}\right)^{\mathrm{7}/\mathrm{2}} \right]_{\mathrm{1}} ^{\mathrm{3}} −\frac{\mathrm{84}}{\mathrm{5}}\left[\left({u}+\mathrm{7}\right)^{\mathrm{5}/\mathrm{2}} \right]_{\mathrm{1}} ^{\mathrm{3}} +\mathrm{49}\left[\left({u}+\mathrm{7}\right)^{\mathrm{3}/\mathrm{2}} \right]_{\mathrm{1}} ^{\mathrm{3}} \\ $$$$=… \\ $$