Question Number 223786 by Nicholas666 last updated on 04/Aug/25
$$ \\ $$$$\:\:\:\:\boldsymbol{\mathrm{Evaluate}}\:;\:\int\:\sqrt{\:\boldsymbol{\mathrm{tan}}\:\boldsymbol{{x}}}\:\boldsymbol{\mathrm{d}{x}}\:,\:\boldsymbol{\mathrm{Using}}\:\boldsymbol{\mathrm{feynman}}'\boldsymbol{\mathrm{s}}\:\boldsymbol{\mathrm{trick}} \\ $$$$ \\ $$
Commented by Frix last updated on 05/Aug/25
$$\mathrm{I}'\mathrm{ll}\:\mathrm{do}\:\mathrm{it}\:\mathrm{but}\:\mathrm{only}\:\mathrm{if}\:\mathrm{you}\:\mathrm{solve} \\ $$$${x}^{\mathrm{3}} +{x}^{\mathrm{2}} −\mathrm{7}{x}−\mathrm{15}=\mathrm{0} \\ $$$$\mathrm{using}\:\mathrm{Ellipitic}\:\mathrm{Functions} \\ $$
Commented by MathematicalUser2357 last updated on 05/Aug/25
The Feynman's trick is the trick that you can solve integrals of a square root of a trigonometric function.
But why do you solve a cubic equation by Elliptic functions������
Commented by Frix last updated on 05/Aug/25
Why would I use Feynman's trick on an integral which can be easily solved without using it, but will get very much harder by using it?
If you have a reason: also make it the reason to solve a cubic by Elliptic functions. ��
Commented by klipto last updated on 07/Aug/25
$$\mathrm{sharp}\:\mathrm{lol} \\ $$