ClearAll[x] integrand = Tan[x]/Sqrt[Sec[x]^3 + 1]; res = Integrate[integrand, x] TeXForm[res]
\[ -\frac {2}{3} \tanh ^{-1}\left (\sqrt {\sec ^3(x)+1}\right ) \]
<< Rubi` ClearAll[x] integrand = Tan[x]/Sqrt[Sec[x]^3 + 1]; res = Int[integrand, x] TeXForm[res]
\[ -\frac {2}{3} \tanh ^{-1}\left (\sqrt {\sec ^3(x)+1}\right ) \]
restart; integrand := tan(x)/sqrt(sec(x)^3 + 1); res:=int(integrand,x); latex(res)
\[ -{\frac {2}{3}{\rm arctanh} \left (\sqrt { \left ( \sec \left ( x \right ) \right ) ^{3}+1}\right )} \]
set output tex off setSimplifyDenomsFlag(true) integrand := tan(x)/sqrt(sec(x)^3 + 1); res:=integrate(integrand,x); latex(res)
\[ {\log \left ( {{{2 \ {{{\cos \left ( {x} \right )}} \sp {3}} \ {\sqrt {{{{{{\cos \left ( {x} \right )}} \sp {3}}+1} \over {{{\cos \left ( {x} \right )}} \sp { 3}}}}}} -{2 \ {{{\cos \left ( {x} \right )}} \sp {3}}} -1}} \right )} \over 3 \]
integrand : tan(x)/sqrt(sec(x)^3 + 1); res : integrate(integrand,x); tex(res)
\[ {{\log \left (\sqrt {{{1}\over {\cos ^3x}}+1}-1\right )}\over {3}}-{{ \log \left (\sqrt {{{1}\over {\cos ^3x}}+1}+1\right )}\over {3}} \]
integrand := tan(x)/sqrt(sec(x)^3 + 1); res := integrate(integrand,x); latex(res)
\[ 2 \left (-\frac {\ln \left (\sqrt {\left (\frac 1{\cos x}\right )^{3}+1}+1\right )}{6}+\frac {\ln \left |\sqrt {\left (\frac 1{\cos x}\right )^{3}+1}-1\right |}{6}\right ) \]
>python Python 3.7.3 (default, Mar 27 2019, 22:11:17) [GCC 7.3.0] :: Anaconda, Inc. on linux from sympy import * x = symbols('x') integrand = tan(x)/sqrt(sec(x)**3 + 1); res = integrate(integrand,x); latex(res)
\[ \text {did not solve} \]
evalin(symengine,'int(tan(x)/sqrt(sec(x)^3 + 1),x)')
\[ \text {did not solve} \]