(3)lim(x->∞) (1+ 1/x) ^(x/2)=[lim(x->∞) (1+ 1/x) ^x]^(1/2)= e^(1/2)(4)lim(x->0) [ 1+ 3(tanx)^2]^(cotx)^2=lim(x->0) [ 1+ 3(tanx)^2]^[1/(tanx)^2]=lim(x->0) [ 1+ 3x^2]^(1/x^2)=e^3