what is the value of B for the vector [2,4,-6]

Question

what is the value of B for the vector [2,4,-6]? 

Answer 1

IF B is the distance from the origin to the point (2,4,-6) use the distance formula

d^2 = sum of squares =4 + 16 +36 = 56

d = sqr56 = 2sqr14 = about 7.48

take each coordinate and square it, then sum them, then take the square root

2x2 = 4

4x4 = 16

-6x-6 = 36

4+16+36 = 56

sqr56 = about 7.48