Dik vektor a=2i+2j+2k dan b=3i+2j+k Jika a+2b=c maka IcI = Mohon bantuannya

2i+2j+2k+2(3i+2j+k) = 2i+2j+2k+6i+4j+2k = 8i+6j+4k

a+2b = (2,2,2)+2(3,2,1) = (2,2,2)+(6,4,2) = (8,6,4)
|c| = akar (8^2+6^2+4^2) = akar (64+36+16) = 2 akar 29