Matrices and determinants

2000017106

Level: 
B
For what values of the real parameters a, b, c, d, e and f will the matrices given below be inverse to each other? (100011abc),(def−11−1101)
a=−1, b=0, c=1, d=1, e=0, f=0
a=1, b=0, c=1, d=−1, e=0, f=1
a=−1, b=0, c=−1, d=1, e=0, f=0
a=1, b=0, c=−1, d=−1, e=1, f=0

2000017210

Level: 
B
In the following matrix, what is the position of the entry with the largest value? (1+2sin⁡π4tg3π43+cos⁡π2235+tg(−π)233−4sin⁡2π−2)
It lays above the main diagonal.
It lays on the main diagonal.
It lays under the main diagonal.
It lays on the counterdiagonal.