帮算几道积分题.

题目

帮算几道积分题.
1.∫2xdx/(1+x)(1+x²)²
2.∫dx/(sin²x+tg²x)
3.∫xdx/(1+x)√(1-x-x²)
1
4.∫e^(x/2)dx/√[e^x+e^(-x)]
0

答案

1.∫2*x/((1+x)*(1+x^2)^2)*dx=1/4*(2*x-2)/(1+x^2)+1/4*ln(1+x^2)-1/2*ln(x+1)+C2.∫1/(sin(x)^2+tan(x)^2)*dx=1/4*tan(1/2*x)-1/4/tan(1/2*x)-1/16*2^0.5*ln((tan(1/2*x)^2+tan(1/2*x)*2^0.5+1)/(tan(1/2*x)^2-tan...