plz don't handwriting solutions

2 a. If A3*3 is a symmetric matrix with |A|= 0 and tr(A)

2 a. If A3*3 is a symmetric matrix with IAI= 0 and tr(A) < 0, then what are the possible definite of A? Why? b. Prove that if all eigenvalues ofa symmetric matrix An*n are positive, then An*n is a positive definite matrix