Find the measure of the angle u13 and v2 6 find each of the

Find the measure of the angle u={-1,3} and v={2, -6}, find each of the following

(a) u+v ( b) -3v (c) u•v (d)|u|

Solution

u = -1i+3j

v = 2i-6j

a) u+v = (-1+2)i+(3-6)j = 1i-3j

b) -3v = 6i-18j

c) u.v = (-1×2)+(3×-6) = -2-18 = -20

d) |u| = {(-1)^2+2^2} = {1+4} = 5