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David E Speyer
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Following up on Anthony Quas's post, let $g(x) = 4x(1-x)$ and $h(x) = \sin(\pi x)$. The equations $g^{(n)}(x) = 1/2$ and $h^{(n)}(x) = 1/2$ each have $2^n$ roots in $[0,1]$. If we sort those roots in order as $y_1 < y_2 < \cdots < y_{2^n}$ and $z_1 < z_2 < \cdots < z_{2^n}$, we should have $f(y_i) = z_i$.

Here is a plot, and list of values, for $n=6$:

enter image description here

0.0002     0.0005
0.0014     0.0033
0.0038     0.0079
0.0074     0.0132
0.0121     0.0211
0.0181     0.0282
0.0252     0.0369
0.0335     0.0465
0.0429     0.0604
0.0534     0.0716
0.0650     0.0832
0.0776     0.0942
0.0912     0.1092
0.1058     0.1220
0.1214     0.1375
0.1379     0.1546
0.1552     0.1790
0.1734     0.1974
0.1924     0.2153
0.2121     0.2310
0.2325     0.2505
0.2536     0.2659
0.2752     0.2833
0.2974     0.3012
0.3201     0.3262
0.3432     0.3454
0.3666     0.3651
0.3904     0.3835
0.4145     0.4082
0.4388     0.4292
0.4632     0.4543
0.4877     0.4813
0.5123     0.5187
0.5368     0.5457
0.5612     0.5708
0.5855     0.5918
0.6096     0.6165
0.6334     0.6349
0.6568     0.6546
0.6799     0.6738
0.7026     0.6988
0.7248     0.7167
0.7464     0.7341
0.7675     0.7495
0.7879     0.769
0.8076     0.7847
0.8266     0.8026
0.8448     0.821
0.8621     0.8454
0.8786     0.8625
0.8942     0.878
0.9088     0.8908
0.9224     0.9058
0.9350     0.9168
0.9466     0.9284
0.9571     0.9396
0.9665     0.9535
0.9748     0.9631
0.9819     0.9718
0.9879     0.9789
0.9926     0.9868
0.9962     0.9921
0.9986     0.9967
0.9998     0.9995
David E Speyer
  • 156.3k
  • 14
  • 421
  • 763