%% Find Closed-Form Solution
% Find the closed-form solution of the integral \int x\;\tan \left(\log \left(x\right)\right)\textrm{dx}.
% Define the integral using the int function.

syms x
F = int(x*tan(log(x)),x)

% The int function cannot find the closed-form solution of the integral.
% Substitute the expression log(x) with t. Apply integration by substitution.

syms t
G = changeIntegrationVariable(F,log(x),t)

% The closed-form solution is expressed in terms of hypergeometric functions. For more details on hypergeometric functions, see hypergeom.
%
% Copyright 2019 The MathWorks, Inc.