What is #|| <-1, 9, -2 > - < 9 , -4, 1 > ||#?

1 Answer
Mar 28, 2016

Answer:

#|V_r|= sqrt(278)~~16.67#

Explanation:

This effectively asking you to find the magnitude of the vector sum.
Solution Strategy:
1) Perform vector addition (subtraction)
2) Compute the magnitude of the new vector, #V_r#
Let #vec(V_1) = -i+9j-2k, and vec(V_2) = 9i-4j-k#
Then 1)
#V_r = V_1 - V_2=-i+9j-2k -(9i-4j-k)#
#V_r=(-1-9)I+(9-(-4)j +(-2-1)k#
#V_r= -10i+13j-3k#
and 2)
#|V_r| = sqrt[(-10^2+13^2+3^2) ]= sqrt[278]#