How do you graph r=3θ?

1 Answer
Feb 9, 2017

Really, the graph ought to be a spiral, with randθ from 0.

Explanation:

I assume that θ is in radian and 3 in 3θ is in distance

units.

The graph is a spiral, with both randθ[0,).

There are problems in using Socratic utility.

Firstly, r=x2+y2=3θ0.

Upon using the Cartesian form

x2+y2=arctan(yx),

the graph obtained is inserted.

The branch in Q1 is for r[0,32π). It is OK.

The branch in Q3 is r-negative graph, for r=3arctan(yx), for

θ(π2,π]. Here, r(32π,0].

Really, r with θ.

graph{sqrt(x^2+y^2)=3arctan(y/x)[-10, 10, -5, 5]}

Short Table for graphing from data, with θ=0(π8)π2:

(r,θradian):(0,0)(1.18,0.39)(2.36,0.79)(3.53,1.18)(4.71,1.57)