∫4/(1-2x)²dx=-2∫1/(1-2x)²)d(1-2x)=2∫d1/(1-2x)=2/(1-2x) + C (C是常数)∫x(x²+3)^(1/2)dx=1/2*∫(x²+3)^(1/2)d(x²+3)=1/2*2/3*∫d(x²+3)^(3/2)=[(x²+3)^(3/2)]/3 + C
