et u be a vector Select the best statement A The vector 4u c

et u be a vector.

Select the best statement.

A. The vector 4u could be longer or shorter than 5u, depending on the choice of u.
B. The vector 4u is always shorter than 5u.
C. The vector 4u is always longer than 5u.
D. The vector 4u is shorter than 5u as long as u is nonzero.
E. The vector 4u is longer than 5u as long as u is nonzero.
F. none of the above

Solution

Option D The vector 4u is shorter than 5u as long as u is nonzero.

since lenght of 4u is |4u| = 4|u|

lenghth of -u is |-5u| = 5|-u| = 5|u|

4|u| < 5|u|