Finding angle for this resultant vector

[RandellK02]

Hello I am working on this problem and just can't figure it out...


Consider two displacements, one of magnitude 3.0 m and another of magnitude 3.8 m. What angle between the directions of this two displacements give a resultant displacement of magnitude (a) 5.7 m, (b) 2.5 m, and (c) 3.6 m.



I have tried to draw the triangle and then use law of cosines and sines to find the appropriate angle but it seems to not be going the way I want it. Is this the correct solution or is there another way to go?

Any help is greatly appreciated.

 

[tiny-tim]

Welcome to PF!

Hello RandellK02! Welcome to PF!

I have tried to draw the triangle and then use law of cosines and sines to find the appropriate angle but it seems to not be going the way I want it. Is this the correct solution or is there another way to go?

It should work.

(You are drawing the two given sides head-to-tail, aren't you?)

Show us one of your attempts. ​

 

[RandellK02]

Okay I will retry my math.
Thanks

 

[denxnis]

Website states this is Incorrect.

Consider two displacements, one of magnitude 2.9 m and another of magnitude 4.4 m. What angle between the directions of this two displacements give a resultant displacement of magnitude (a) 5.6 m, (b) 2.9 m, and (c) 4.6 m.

98.1
40.7
75.0