A boat sails 4km on a bearing of 038 degree and then 5km on a bearing of 067 degree.(a)how far is the boat from its starting point.(b) calculate the bearing of the boat from its starting point

14 answers

simplest way is using vectors.
resultant vector
= (4cos38,4sin38) + (5cos67,5sin67)

= (3.152.., 2.4626..) + (1.9536..., 4.6025..)
= (5.1056.., 7.065...)

distance = √(5.1056..^2 + 7.065.^2)
= appr 8.717 correct to 3 decimals

bearing:
tanØ = 7.065../5.1056..
Ø = 54.146°

OR

Using basic geometry:
make a sketch, on mine I have a triangle with sides 4 and 5 with an angle of 151° between them
by the cosine law:
d^2 = 4^2 + 5^2 - 2(4)(5)cos151
= 8.717 , just like above

let the angle opposite the 5 km side be Ø
by the sine law:
sinØ/5 = sin 151/8.717
sinØ = .27808..
Ø = 16.146
bearing = Ø + 38°
= 16.146+38
= 54.146° , again, just as above
I don't understand
which formula am i going to use to solve it
A ship sail 4km on a bearing of 038 and then 5km on a bearing of 067 calculate the distance between the starting point and final destination and the bearing ship from the starting point.
Pls questions
A ship sails 4km on a bearing of 038° and then 5km on a bearing of 0670
Calculate:
A. The distance between the starting point and final destination
B: the bearing of the ship from it starting point
I want the full full explanation
i love this
pls how did u get 151
How did u get .27808...
Did u cross multiply?
How did you get38
What about the bearing from d boat to the starting point or whatever
I want the full explanation
The basic geometry is very difficult to understand