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Category: Integration

Let-consider-a-n-n-and-u-n-n-two-reals-sequence-defined-such-as-a-0-1-n-gt-1-a-n-1-p-0-n-a-p-a-n-p-and-p-0-n-a-p-u-n-p-0-Part1-1-Express-n-gt-1-a-n-i

Question Number 68220 by ~ À ® @ 237 ~ last updated on 07/Sep/19 $$\:\:\:{Let}\:{consider}\:\left({a}_{{n}} \right)_{{n}} \:{and}\:\left({u}_{{n}} \right)_{{n}} \:{two}\:{reals}\:\:{sequence}\:\: \\ $$$${defined}\:{such}\:{as}\:\:\:{a}_{\mathrm{0}} =\mathrm{1}\:,\:\forall\:{n}>\mathrm{1}\:\:{a}_{{n}+\mathrm{1}} =\underset{{p}=\mathrm{0}} {\overset{{n}} {\sum}}{a}_{{p}}…

Let-consider-a-n-n-and-u-n-n-two-reals-sequence-defined-such-as-a-0-1-n-gt-1-a-n-1-p-0-n-a-p-a-n-p-and-p-0-n-a-p-u-n-p-0-Part1-1-Express-n-gt-1-a-n-i

Question Number 68219 by ~ À ® @ 237 ~ last updated on 07/Sep/19 $$\:\:\:{Let}\:{consider}\:\left({a}_{{n}} \right)_{{n}} \:{and}\:\left({u}_{{n}} \right)_{{n}} \:{two}\:{reals}\:\:{sequence}\:\: \\ $$$${defined}\:{such}\:{as}\:\:\:{a}_{\mathrm{0}} =\mathrm{1}\:,\:\forall\:{n}>\mathrm{1}\:\:{a}_{{n}+\mathrm{1}} =\underset{{p}=\mathrm{0}} {\overset{{n}} {\sum}}{a}_{{p}}…

Find-the-arc-length-given-the-curve-x-t-sin-pit-y-t-t-0-t-1-

Question Number 68145 by Joel122 last updated on 06/Sep/19 $$\mathrm{Find}\:\mathrm{the}\:\mathrm{arc}\:\mathrm{length},\:\mathrm{given}\:\mathrm{the}\:\mathrm{curve} \\ $$$${x}\left({t}\right)\:=\:\mathrm{sin}\:\left(\pi{t}\right),\:\:{y}\left({t}\right)\:=\:{t}\:,\:\:\mathrm{0}\:\leqslant\:{t}\:\leqslant\:\mathrm{1} \\ $$ Commented by Joel122 last updated on 06/Sep/19 $${x}'\left({t}\right)\:=\:\pi\:\mathrm{cos}\:\left(\pi{t}\right),\:{y}'\left({t}\right)\:=\:\mathrm{1} \\ $$$$ \\…

the-2-formulas-for-solving-dx-x-3-px-q-with-nasty-solutions-of-x-3-px-q-0-with-p-q-R-case-1-D-p-3-27-q-2-4-gt-0-x-3-px-q-0-has-got-1-real-and-2-conjugated-complex-solutions-u-

Question Number 68141 by MJS last updated on 06/Sep/19 $$\mathrm{the}\:\mathrm{2}\:\mathrm{formulas}\:\mathrm{for}\:\mathrm{solving}\:\int\frac{{dx}}{{x}^{\mathrm{3}} +{px}+{q}}\:\mathrm{with} \\ $$$$“\mathrm{nasty}''\:\mathrm{solutions}\:\mathrm{of}\:{x}^{\mathrm{3}} +{px}+{q}=\mathrm{0}\:\mathrm{with}\:{p},\:{q}\:\in\mathbb{R} \\ $$$$ \\ $$$$\mathrm{case}\:\mathrm{1} \\ $$$${D}=\frac{{p}^{\mathrm{3}} }{\mathrm{27}}+\frac{{q}^{\mathrm{2}} }{\mathrm{4}}>\mathrm{0}\:\Rightarrow\:{x}^{\mathrm{3}} +{px}+{q}=\mathrm{0}\:\mathrm{has}\:\mathrm{got}\:\mathrm{1}\:\mathrm{real} \\ $$$$\mathrm{and}\:\mathrm{2}\:\mathrm{conjugated}\:\mathrm{complex}\:\mathrm{solutions}…

1-1-x-dx-

Question Number 133674 by liberty last updated on 23/Feb/21 $$\int\:\sqrt{\mathrm{1}+\sqrt{\mathrm{1}+\sqrt{\mathrm{x}}}}\:\mathrm{dx}\:=?\: \\ $$ Answered by EDWIN88 last updated on 23/Feb/21 $$\:\mathrm{let}\:\mathrm{y}\:=\:\sqrt{\mathrm{1}+\sqrt{\mathrm{1}+\sqrt{\mathrm{x}}}}\:\Rightarrow\sqrt{\mathrm{1}+\sqrt{\mathrm{x}}}\:=\:\mathrm{y}^{\mathrm{2}} −\mathrm{1} \\ $$$$\Rightarrow\mathrm{1}+\sqrt{\mathrm{x}}\:=\:\mathrm{y}^{\mathrm{4}} −\mathrm{2y}^{\mathrm{2}} +\mathrm{1}\:,\:\mathrm{x}\:=\:\left(\mathrm{y}^{\mathrm{4}}…