Question

高等数学 两道计算题 求详细点的解题过程，谢谢！

Answer 1

dy/dx=(dy/dt)/(dx/dt)
=(1/(1+t²))/(2t/(1+t²))
=1/2t
d²y/dx²=(d(dy/dx)/dt)/(dx/dt)
=(-1/2t²)/(2t/(1+t²))
=-(1+t²)/4t³

追答

=-1/2∫sin(2/x+3)d(2/x+3)
=cos(2/x+3)/2+C