Physics
posted by nelly .
Vector ~A has a magnitude of 7 and points in the positive xdirection. Vector ~B has a magnitude of 21 and makes an angle of 30â—¦ with the positive xaxis.
What is the magnitude of ~A âˆ’ ~B ?

X = 7 + 21Cos(30) = 7 + 18.19 = 25.19,
Y = 21Sin(30) = 10.5,
Z^2 = X^2 + Y^2 = (25.19)^2 + (10.5)^2 = 634.54 + 110.25 = 744.8,
Z = sqrt(744.8) = 27.3 = Magnitude.