(a) Find the MRS of
x_(1)
for
x_(2)
for each of the following utility functions: I.
,U(x_(1),x_(2))=x_(1)+x_(2)
II.
,U(x_(1),x_(2))=x_(1)^((1)/(2))x_(2)^((1)/(2))
III.
,U(x_(1),x_(2))=x_(1)^(2)+x_(2)^(2)
IV.
,U(x_(1),x_(2))=2x_(2)+x_(1)