PreCal
posted by Jack .
Find the distance between P1(3, –195°) and P2(–4, –94°) on the polar plane. Round your answer to the nearest thousandth.

P2(4,94°) can also be written a (4,94°)
Make a sketch to see that you have two straight lines with vertex at the origin of lenghts 3 and 4 with an angle of 79° between them.
by the cosine law:
(P1P2)^2 = 3^2 + 4^2  2(3)(4)cos 79°
= 20.42056
P1P2 = 4.519 
Thanks, I am understanding now.