Integral 1 + 4x /√1+x+2x² dx

∫4x/(1-2x^2)^1/2 dx = ∫4x(1-2x²)^-1/2 dx

=∫4x(u)^-1/2 du/dx

=∫4x(u)^-1/2 du/-4x

=∫-(u)^-1/2 du

=-2(1-2x²)^1/2 + c

=-2² sqrt{1-2x}
+1