Model for Elementary Analytic Geometry by Richard P. Baker, Baker #230
date: label: date made
content: ca 1906-1935
name: label: maker
content: Baker, Richard P.
notes: label: Description
content: This geometric model was constructed by Richard P. Baker in the early twentieth century when he was Associate Professor of Mathematics at the University of Iowa. Baker believed that models were essential for the teaching of many parts of mathematics and physics, and over 100 of his models are in the museum collections.
label: Description
content: The images of this model show portions of two curves in two dimensions with a paper label attached to one of the metal curves. The typed part of this label reads: “No. 230 (/) Cos=cos cos+cos cos+cos (/) cos” with handwritten θ, α, α’, β, β’, γ, and γ’ following the seven instances of cos. As these angles are not shown on the model as it now exists, it is likely that what is labeled as Baker’s model 230 is only part of the model that represents the equation on its label.
label: Description
content: However, the equation as written does have a clear geometric meaning related to what are known as direction cosines of a vector, i.e., the cosines of the angles that the vector makes with the x, y, and z axes. Specifically, if the angles two vectors make with the axes are α, β, γ, and α’, β’, γ’ then the equation given as the title of this model, cos θ = cos α cos α’ + cos β cos β’ + cos γ cos γ’, says that θ is the angle between the two vectors.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Frances E. Baker
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.211257.039
label: accession number
content: 211257
label: catalog number
content: 211257.039
objectType: label: Object Name
content: geometric model
physicalDescription: label: Physical Description
content: metal (overall material)
label: Physical Description
content: black (overall color)
label: Physical Description
content: soldered (overall production method/technique)
label: Measurements
content: average spatial: .1 cm x 17.9 cm x 10.3 cm; 1/32 in x 7 1/16 in x 4 1/16 in