Descartes's machine used to plot points on the graph of a logarithm function

Check all boxes in order to see the stages of the construction.
Move points H and A_1 to adjust the shape of the graph.

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Descartes's mean proportionals/logarithm machine can be used to plot points on the graph of a logarithm function, y=log_b(x). The base b of the logarithm can be changed by adjusting points H and A_1.

See Descartes's Logarithm Machine for a full explanation.

Related demonstration files:
Similar right triangles
Geometric means
Descartes's mean proportionals/logarithm machine
Descartes's machine used to solve a "two mean proportionals" problem
Descartes's machine used to plot points on the graph of a logarithm function
Descartes's construction used to find the slope of a tangent to a logarithmic graph

Susan Addington, Created with GeoGebra