Explain why a point in the polar plane cannot be named by a unique ordered

pair (r, theta).

 you can describe any point but you can describe the same point in potentially infinite ways. 
example; the rectangular coordinate of (1,1) 

in polar you can describe this point as (pi/4,1) or (5pi/4, -1) and so on

Thank you for posting your question here at . I hope the answer will help you. Feel free to ask more questions.

Fraction division is basically multiplication of a reciprocal.

For example (1/4)/(1/8) = (1/4)x(8/1)=2

Multiplication of the answer and the piece that divides (in this case 2 x 1/8), you should get the piece that is being divided (in this case 1/4). If that is correct, then your division is correct.