Asked by Tammy Evert

Add the following vectors using trigonometry (i.e. cosine and sine laws). 9 N on a heading of [S2°W] and 11 N on a heading of [N31°W].?
Answered by Reiny
[S2°W] ---> 268°
[N31°W] ---> 121° in standard trig notation

Resultant = 9(cos268° , sin268°) + 11(cos 121°, sin 121°)
= .....
Answered by Henry2
All angles are measured CCW from +X-axis
Fr = 9N[268 ]+ 11N[121o].
X = 9*Cos268 + 11*Cos121 =
Y = 9*sin268 + 11*sin121 =

Fr = sqrt(X^2 + Y^2).
TanA = Y/X.