A few nice Computer images I found:
Image from page 59 of “Trigonometria” (1658)
Image by Internet Archive Book Images
Year: 1658 (1650s)
Authors: Newton, J.
Contributing Library: The Computer Museum Archive
Digitizing Sponsor: Gordon Bell
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Text Appearing Before Image:
Text Appearing After Image:
As the t Argent of the halffum of the two acute angles in a right a ngled triangle,■ Is to the tangent oftheir half difference : So ii the tangent of the half fumme of the opfofite angles in An oblique angled triangle,7 o the tangent of their half difference. D E M0NSTR.ATION. Let the fides A C and A B in the oblique angled triangle A B C,be equal to the fides D F and and FE, in the right angled triangle;^E. ^ I fay then, As the fumme of AC and A B, is to the diffe-r ence of AC and AB.So is the tangent of the half fumme of the an-Ji gles at C and B, to the tang, of half their differ.As the fum of D? C^FE is to the df. o/DF^FE.So is the tang, of the half fumme of the angles at D and E, to the tang, of half their difference, by thefirft variety of this propofition; Therefore , As the tangent of the half fnmme of the angles atD and E, is to the tangent of half thetr difference.So is the tangent of the halffnmme of the angles at C and B, to the tangent of half their difference, aswas to
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