# Graphing a circle with vectors/arrows

I have a question that i'm unsure of how to do.

Making the two circles are not a problem but I'm stuck on how to proceed for step 2. Could I get some assistance please?

a) Two circles centered at the original point, one with the radius of 2, in red color, and another with radius of 3, in blue color

b) Two set of vectors, one consists of vectors from the original point to the point (2cos(x), 2sin(x)) as x ranges from 0 to 2π in intervals of π/16 , and another consists of vectors from the point (3cos(x), 3sin(x)), to the point (2cos(x), 2sin(x)), as x ranges from 0 to 2π by intervals of π/16 . Note: All vectors of two sets are in red. The result should be same as the figure on the next page

## 1 Answer

divs = Transpose @ Through @ {Cos, Sin} @ Subdivide[0, 2 Pi, 32];

{r1, r2} = {2, 3};

Graphics[{Thick, Blue, Circle[{0, 0}, r2], Red, Circle[{0, 0}, r1],
Thin, Arrowheads[{{-.05, r1/r2}, {.05, r1/r2}}], Arrow[{{0, 0}, r2 #}] & /@ divs},
PlotRangePadding -> Scaled[.08],
ImagePadding -> 40,
AxesStyle -> Directive[14, Black, Arrowheads[.05]],
Axes -> True,
AxesLabel -> (Style[#, 16] & /@ {"x", "y"}),
Background -> RGBColor[0.8354, 0.8, 0.6315],
ImageSize -> Large] 