Lesson 11.3: Vectors
Vectors are often displayed as letters with arrows above them similar to rays. However, vectors may also be shown as boldfaced lower case letters and appear without an arrow. A double-barbed arrow or a single-barbed arrow may be displayed above the letters. The most common usage is a single-barbed arrow with the barb to the right and on top of the shaft. This might also be referred to as a half-barb. In general, a full-barbed arrow indicates a ray and a single-barbed arrow indicates a vector.
Sometimes a text may consistently display arrows above vectors that are also displayed in bold print. If arrows are consistently used above vectors that are also shown in boldface type throughout a text, the arrows must be omitted in braille unless the author specifically refers to the vectors with the arrows, as part of a notational explanation. The boldface font is enough of an indication that the symbol shown is a vector in both print and in braille. Therefore, a the vector displayed as a bold v with an arrow over it would normally be displayed simply as
the vector n displayed with a half-barbed arrow
the sum of two vectors n and u
the vector m equals two thirds open paren vector v minus vector u close paren
Find the magnitude of the vector a.