 | Samuel Johnson - 1812 - 808 sider
...the rays meet and cross the axis after their refraction by the class. //orris. 9 Foctu of a Parabola. A point in the axis within the figure, and distant from the vertex by a fourth pan of the parameter, or laliu rrctum. Harrii. 3 Fans of aw EUiptit. A point toward each end of the... | |
 | Walter Hamilton - 1825 - 486 sider
...meet, and cross the axis after their refraction by the glass. Focus of a PARABOLA. In Mathematics, a point in the axis within the figure, and distant from the vextex by a fourth part of the parameter or latw rectum. Focus of an ELLIPSE. In Geometry, a point... | |
 | Thomas Curtis - 1829 - 822 sider
...several rays meet, or are collected after being either reflected or refracted. Foci's OF л PARABOLA, rces continue to be in equilibrio, the bird will remain suspended in the same place ; for the bird on or latus rectum. Foccs OF AN ELIPSIS, a point towards each end of the longer axis ; from whence two... | |
 | Thomas Curtis (of Grove house sch, Islington) - 1839 - 864 sider
...are collected after being either reflected or refracted. Focus OF A PARABOLA, a point in the а\ь within the figure, and distant from the vertex by a fourth part of the parameter, or latts rectuai. Focus OF AN ELIPSIS, a point towards each end of the longer axis ; from whence two... | |
 | William Bolles - 1845 - 954 sider
...meet and cross the axis after their refraction by the glass. Focus of a Parabola: A point in the ini.i within the figure, and distant from the vertex by a fourth part of the parameter. Focus of tin EUip .'?.?.- A point toward each end of the longer axis ; whence two right lines being... | |
 | William Bolles - 1846 - 960 sider
...concourse, where the rays meet and cross the axis after their refraction by the glass. Focia of a Parabola: A point in the axis within the figure, and distant...from the vertex by a fourth part of the parameter. Focus of an Ellipsis: A point toward each end of the longer axis ; whence two right lines being drawn... | |
 | W. M. Buchanan - 1846 - 768 sider
...glass is the point of convergence where the rays cross the axis after their refraction by the glass. The focus of a parabola is a point in the axis within the ngure, and distant from the vertex by a fourth part of the parameter or latus rectum. The foci of an... | |
 | James Knowles - 1851 - 818 sider
...concourse, where the rays meet and cross the axis after their refraction by the glass. Focus of a Panibala : A point in the axis within the figure, and distant...from the vertex by a fourth part of the parameter. For us of an Ellipsis : A point towards each end of the longer axis ; from whence two right lines being... | |
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In optics, the focus of a glass is the point of convergence or concourse, where the rays meet and cross the axis after their refraction by the glass. 