Question 1155217
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Vector v = (15*cos(60°),15*sin(60°)).


Vector u = (25*cos(140°),25*sin(140°)).


Vector u + v = (15*(cos(60°) + 25*cos(140°), 15*sin(60°) + 25*sin(140°))


If "a" is the direction angle for the resultant, then


    tan(a) = {{{(15*sin(60^o) + 25*sin(140^o))/(15*cos(60^o) + 25*cos(140^o))}}}.


So, calculate tan(a) using this formula.


Then  a = arctan of this value.
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Having clear instructions, you may complete calculations on your own.