Question

Ex 1 . Se considera matricea

Answer 1

a) Det A(x)=0 => (x-1)(x+1)-3x1=0 ,
dar (x-1)(x+1)= x^2-1^2 
=>x^2-1-3=0 =>x^2=4 => x=2
b)A(1)= (0 3/1 1) => A(1)^2= (3 3/ 3 4) => 3A(1)^2= (9 9/9 12)
c) A(-1) = (-2 3/1 0)
I2= (1 0/ 0 1) 
=> A(-1) - I2 = (-3 3/ 1 -1)