Question

Resultant Force: Forces with magnitudes of 125 newtons and 300 newtons act on a hook. The angle between the two forces is 45*. Find the direction and magnitude of theresultant of these forces.

Tried using this formula IIRII = (square root) of (force 1)squared + (force 2) squared

but my answer wasn't the one in the back of the book

can you help me with the correct formula(s) to use

Answer 1

Magnitude is v( ( 125 + 300 cos 45 )^2 + (300 sin 45)^2 ) = 398 N

Answer 2

magnitude of the resultant of these forces is 398.32 N
formula is F1^2 + F2^2 + 2F1F2cos45