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Category: Integration

Question-74394

Question Number 74394 by aliesam last updated on 23/Nov/19 Commented by mathmax by abdo last updated on 23/Nov/19 $$\left.\mathrm{1}\right)\:{let}\:{decompose}\:{F}\left({x}\right)=\frac{\mathrm{4}{x}^{\mathrm{2}} +{x}}{{x}^{\mathrm{3}} −\mathrm{81}{x}}\:\Rightarrow{F}\left({x}\right)=\frac{\mathrm{4}{x}^{\mathrm{2}} +{x}}{{x}\left({x}−\mathrm{9}\right)\left({x}+\mathrm{9}\right)} \\ $$$$=\frac{\mathrm{4}{x}+\mathrm{1}}{\left({x}−\mathrm{9}\right)\left({x}+\mathrm{9}\right)}\:=\frac{{a}}{{x}−\mathrm{9}}\:+\frac{{b}}{{x}+\mathrm{9}} \\…

find-x-x-1-2-x-1-3-dx-

Question Number 74346 by mathmax by abdo last updated on 22/Nov/19 $${find}\:\int\:\:\frac{{x}+\sqrt{{x}+\mathrm{1}}}{\mathrm{2}\sqrt{{x}−\mathrm{1}}+\mathrm{3}}{dx} \\ $$ Answered by MJS last updated on 24/Nov/19 $$\int\frac{{x}+\sqrt{{x}+\mathrm{1}}}{\mathrm{3}+\mathrm{2}\sqrt{{x}−\mathrm{1}}}{dx}= \\ $$$$\:\:\:\:\:\left[{t}=\mathrm{2}\sqrt{{x}−\mathrm{1}}\:\rightarrow\:{dx}=\sqrt{{x}−\mathrm{1}}{dt}\right] \\…