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  2. Curved mirror - Wikipedia

    en.wikipedia.org/wiki/Curved_mirror

    A curved mirror is a mirror with a curved reflecting surface. The surface may be either convex (bulging outward) or concave (recessed inward). Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices. The most common non-spherical type are parabolic reflectors, found in ...

  3. Virtual image - Wikipedia

    en.wikipedia.org/wiki/Virtual_image

    The magnification of the virtual image formed by the plane mirror is 1. Top: The formation of a virtual image using a diverging lens. Bottom: The formation of a virtual image using a convex mirror. In both diagrams, f is the focal point, O is the object, and I is the virtual image, shown in grey. Solid blue lines indicate (real) light rays and ...

  4. Hyperplane separation theorem - Wikipedia

    en.wikipedia.org/wiki/Hyperplane_separation_theorem

    In geometry, the hyperplane separation theorem is a theorem about disjoint convex sets in n-dimensional Euclidean space.There are several rather similar versions. In one version of the theorem, if both these sets are closed and at least one of them is compact, then there is a hyperplane in between them and even two parallel hyperplanes in between them separated by a gap.

  5. Graham scan - Wikipedia

    en.wikipedia.org/wiki/Graham_scan

    A demo of Graham's scan to find a 2D convex hull. Graham's scan is a method of finding the convex hull of a finite set of points in the plane with time complexity O (n log n). It is named after Ronald Graham, who published the original algorithm in 1972. [ 1 ] The algorithm finds all vertices of the convex hull ordered along its boundary.

  6. Plane mirror - Wikipedia

    en.wikipedia.org/wiki/Plane_mirror

    Plane mirror. A plane mirror showing the virtual image of an urn nearby. A diagram of an object in two plane mirrors that formed an angle bigger than 90 degrees, causing the object to have three reflections. A plane mirror is a mirror with a flat (planar) reflective surface. [1][2] For light rays striking a plane mirror, the angle of reflection ...

  7. Cassegrain reflector - Wikipedia

    en.wikipedia.org/wiki/Cassegrain_reflector

    The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture. This design puts the focal point at a convenient ...

  8. Convex optimization - Wikipedia

    en.wikipedia.org/wiki/Convex_optimization

    Convex optimization is a subfield of mathematical optimization that studies the problem of minimizing convex functions over convex sets (or, equivalently, maximizing concave functions over convex sets). Many classes of convex optimization problems admit polynomial-time algorithms, [1] whereas mathematical optimization is in general NP-hard. [2 ...

  9. Foucault knife-edge test - Wikipedia

    en.wikipedia.org/wiki/Foucault_knife-edge_test

    Foucault knife-edge test. The Foucault knife-edge test is an optical test to accurately measure the shape of concave curved mirrors. It is commonly used by amateur telescope makers for figuring primary mirrors in reflecting telescopes. It uses a relatively simple, inexpensive apparatus compared to other testing techniques.