How would one rearrange to solve for r?
2π2r-(0.2/r)=0
2π2r-(0.2/r)=0
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(2π * 2r) - (0.2/r) = 0
4π.r = 0.2/r
4π.r² = 0.2
π.r² = 0.2/4
π.r² = 0.05
r² = 0.05/π
r = ± √(0.05/π)
r ≈ ± 0.126156
4π.r = 0.2/r
4π.r² = 0.2
π.r² = 0.2/4
π.r² = 0.05
r² = 0.05/π
r = ± √(0.05/π)
r ≈ ± 0.126156