Question

Dada a matriz A= (aij) 2x2, em que aij= 3.i+j², calcule o det (a)

Answer 1

$\sf{a_{11}=3\cdot1+1^2=3+1=4}\\\sf{a_{12}=3\cdot1+2^2=3+4=7}\\\sf{a_{21}=3\cdot2+1^2=6+1=7}\\\sf{a_{22}=3\cdot2+2^2=6+4=10}$

$\sf{det~A=4\cdot10-7\cdot7=40-49=-9}$