courses > ECONO010_21-22 > Assessment > January Multiple Choice Exam 9 Let f(1, 2, 23)= 27 + 23 + 23 + 143. Which one of the following statements is true? Select one: out of O a. f(1, 2) is positive definite O b. f(x1, 2) is negative definite O c. f(1, 2) is positive semidefinite but not positive definite O d. f(1, T2) is negative semidefinite but not negative definite O e. (x x2 ) is none of the above ious page Next page