Question

How do I find the distance between polar coordinates `(3, 60^circ)` and `(5, 145^circ)`?

Answer 1

Using the cosine rule, we get 5.602.

Explanation:

Angle between them is `85^o` one of the length is 3, and other is 5.. Therefore by cosine rule
`a^2+b^2-2abcostheta = c^2`
`=> 9^25-2*3*5*cos85 = c^2`
`=> 34 - 2.614 = 31.386 = c^2`
`=> c = sqrt(31.386) = 5.602`