Question

Dados os vetores u= (2,-3,-1) e v = (1,-1,4)], segue imagem!

Answer 1

u=(2,-3,-1) e v=(1,-1,4)

(u+v)*(u-v)={(2,-3,-1)+(1-1,4)}*{(2,-3,-1)-(1,-1,4)}
=(3,-4,3)*(1,-2,-5)
=3+8-15
=-4



espero ter ajudado!!!

Answer 2

u+v=(2+1,-3+(-1),-1+4)=(3,-4,3)

u-v=(2-1,-3-(-1),-1-4) =(1,-2,-5)

(u+v).(u-v) é o produto escalar

(3,-4,3) . (1,-2,-5)

=3*1-4*(-2)+3*(-5)

=3 + 8 - 15 = -4  

Letra D