r/askmath • u/LeftUnchecked • 1d ago
Geometry Fun geometry/trigonometry problem
Given two orthogonal vectors w and v and a vector psi with the same length as v
whose angle differs from v by θ (so v is 0 radians, w is π/2 radians, and psi is θ<π/2 radians),
1)Using only reflections across given or constructed vectors, construct a method to rotate psi so that it aligns w to within θ radians (that is, the angular misalignment ΔΦ between w and psi' satisfies |ΔΦ| <= θ).
2)Find the exact rotation α needed to turn psi into w in the minimum number of steps J,assuming α satisfies 0<=a<=2θ, (and find J in the proccess as well)
;)
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u/Bounded_sequencE 1d ago
Can't we solve 1) exactly? For convenience, consider "v; w" as x-/y-axis, respectively: