Question

Dada a matriz A=(aij) 3X3 tal que aij=i2+2j-5 calcule a12+a31.

Answer 1

Resposta:

Aij= 2i + 2j - 5

A11= 2×1 + 2×1 - 5 = 2+2-5= -1

A12= 2×1+2×2-5 = 2+4-5=1

A13= 2×1+2×3-5=2+6-5= 3

A21= 2×2+2×1-5=4+2-5= 1

A22= 2×2+2×2-5=4+4-5=3

A23= 2×2+2×3-5=4+6-5=5

A31= 2×3+2×1-5=6+2-5=3

A32= 2×3+2×2-5=6+4-5=5

A33= 2×3+2×3-5=6+6-5=7

A11 A12 A13 -1 1 3

A21 A22 A23 = 1 3 5

A31 A32 A33 3 5 7

A12 + A31 = 1 + 3 = 4