limarcsin(x^3y)/(2^x+y)(x,y)→(1,1/2);limxy/(2-√(xy+4))(x,y)→
2个回答

1))当(x,y)→(1,1/2)时,

limarcsin(x^3y)/(2^x+y)

=arcsin(1^3*1/2)/(2^1+1/2)

=pai/6/(5/2)

=pai/15

2)当(x,y)→(0,0)时,

limxy/(2-√(xy+4))

=limxy*(2+√(xy+4))/[(2-√(xy+4))(2+√(xy+4))]

=limxy*(2+√(xy+4))/[(4-(xy+4)]

=limxy*(2+√(xy+4))/(-xy)

=-lim(2+√(xy+4))

=-[2+√(0+4)]

=-4