Transformation Operations in Algebra: Rotation, Translation & Inversion
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Explore properties of rotation, translation, screw operations, and glides in algebra. Learn about intersecting and parallel mirrors, inversion, and screw axes. Discover the mathematics behind these transformations.
Transformation Operations in Algebra: Rotation, Translation & Inversion
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Algebra of operations Thm 1: Rotation about A thru angle followed by translation T to axis = rotation thru same angle about B on bisector of AA' at T/2 cot (/2) from AA'
Algebra of operations a a -1 a a Thm 1: Rotation about A thru angle afollowed by translation T to axis = rotation thru same angleaabout B on bisector of AA' at T/2 cot (a/2) from AA' A T = B B A T = 1
Algebra of operations a a -1 a a -1 -1 a a Thm 1: Rotation about A thru angle followed by translation T to axis = rotation thru same angle about B on bisector of AA' at T/2 cot (/2) from AA' A T = B B A T = 1 B A = T = T'
Algebra of operations Thm 1: Rotation about A thru angle followed by translation T to axis = rotation thru same angle about B on bisector of AA' at T/2 cot (/2) from AA' A T = B B A T = 1 B A = T = T' a a B -1 a a -1 -1 a a A A'
Algebra of operations -1 -1 Meaning of A B A: The operation B as transformed by A 2 B 3 (2B3) A (1B'4) 1 B' 4 1 A 2 2 B 3 3 A 4 A 2 -1 1 A B' A B 3 4 A
Algebra of operations a,T a a Thm 2: Rotation about A thru angle followed by translation T to axis = screw. Rotation & translation operations permutable A T = T A = A
Algebra of operations a,T a a a a a,T a Thm 2: Rotation about A thru angle followed by translation T to axis = screw. Rotation & translation operations permutable A T = T A = A Then: T = T + T A T = A T T = B T = B
Algebra of operations a,T a a a a a,T a Thm 2: Rotation about A thru angle followed by translation T to axis = screw. Rotation & translation operations permutable A T = T A = A Then: T = T + T A T = A T T = B T = B B screw axis A A'
Algebra of operations 2m 1 2 2 1 Intersecting mirrors: m m = A Parallel mirrors: m T = m
Algebra of operations Inversion: i T = A m T = A m = i p 1, 1 2 p 2,
Algebra of operations p 1, 1 p 2, 2 t Inversion: i T = A m T = A m = i Glides: Define: m = m t
Algebra of operations Inversion: i T = A m T = A m = i Glides: Define: m = m t p 1, 1 p 2 2, Glide symbols t a c axial diagonal diamond 1/8 b n d
Algebra of operations • Inversion: • i T = A m T • = A m = i • Glides: • Define: m = m t • m T = m T T • m T = m 1 1, p p 2, 2 t 1 1 2 2, t
Algebra of operations • Inversion: • i T = A m T • = A m = i • Glides: • Define: m = m t • m T = m T T • m T = m 1 1, p p 2, 2 t 1 1 2 2, t
Algebra of operations • Glides: • m T = m T T • = m T T • = m T • = m t 1 1, t t 1 t 2 2, t +
Algebra of operations • Glides: • m T = m T T • = m T T • = m T • = m t 1 1, t t 1 t 2 2, t +
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' 1 t t p p, t t p
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t t p, t p t p t 1 t -1 2 1
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t t p, t p t p t 1 -1 t 2 1 -1 t i 1 2 t i 1 1 t
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t t p p, t t p t 1 -1 t 2 1 -1 t i 1 2 t i 1 1 t
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t t p p, t t p t 1 -1 t 2 1 -1 t i 1 2 t i 1 1 t
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t t p p, t t p t 1 -1 t 2 1 -1 t i 1 2 t i 1 1 t
Algebra of operations • 2 screw & glide: • A m = A t m • = A m t' • = i t' • = i t = i 1 t p t p, t t p t 1 -1 t 2 1 -1 t i 1 2 t i 1 1 t
Algebra of operations 2m p p • Two 2-fold axes at angle apart: • A B = C' (from Euler calc.) C 2m 2m m 2 2
Algebra of operations • In general: • A B = C' • If screw axes: • A B = t A B t = t C' t • t C t = C' g a b a g a,t b 2 2 a,t 1 1 1 2 -1 g g t t 2 2 t t 1 1 C" C + m 2m C' B A
Algebra of operations • In general: • A B = C' • If screw axes: • A B = t A B t = t C' t • t C t = C' • t C' t = C t t • = C" g b a a,t g a,t b 2 1 2 a 1 1 2 -1 g g 1 g g 2 2 1 C t t 2 2 t t 1 1 C" + m 2m C' B A
Algebra of operations • In general: • A B = C' • If screw axes: • A B = t A B t = t C' t • t C t = C' • t C' t = C t t • = C" b a g a,t a,t a b 2 g 1 1 2 1 2 -1 g g g 2 g 2 1 1 C t t 2 2 Not a screw axis - no t II C t t 1 1 C" + m 2m C' B A
Algebra of operations t t 2 2 t t 1 1 • If screw axes: • A B = t A B t = t C' t • t C t = C' • t C' t = C t t • = C" g 2 a,t a,t b a 1 2 1 2 1 -1 g g g 1 g 1 2 2 C" If A, B do not intersect, but are separated in direction along C, C" has screw axis translation component C + m 2m C' B A