y=x(π/2-arctanx)
所以
lim(x->∞)y=lim(x->∞)x(π/2-arctanx)
=lim(x->∞)(π/2-arctanx)/(1/x)
=lim(x->∞)(-1/(1+x²))/(-1/x²)
=lim(x->∞)x²/(1+x²)
=lim(x->∞)2x/2x
=1
所以
水平渐近线为y=1
y=x(π/2-arctanx)
所以
lim(x->∞)y=lim(x->∞)x(π/2-arctanx)
=lim(x->∞)(π/2-arctanx)/(1/x)
=lim(x->∞)(-1/(1+x²))/(-1/x²)
=lim(x->∞)x²/(1+x²)
=lim(x->∞)2x/2x
=1
所以
水平渐近线为y=1