MACHINE SHOP CALCULATION - OD1640 - LESSON 2/TASK 3
0.96923 on the page marked 75,, at the bottom (see Table 8). In this case,
the minutes are found in the extreme right-hand column. The value of the
minutes corresponding to the number 0.96923 is 45'.
Therefore, angle A =
75,, 45'.
EXAMPLE
Find the value of angle A when cos A = 0.86603.
SOLUTION
According to the preceding note, angle A must be less than 45,,. The number
0.86603 is found at the 30,, column marked "cosine" at the top (Table 9 on
the following page). The value of the minutes, in the left-hand column, is
found to be zero. Therefore, angle A = 30,, 0'.
TABLE 8.
TRIGONOMETRIC TABLE.
EXAMPLE
Find the value of angle A when tan A = 0.18384.
SOLUTION
Evidently angle A is less than 45,,. Therefore, the number 0.18384 is found
in the "tangent" column with the heading at the top of the 10,, page (Table
10 on the following page). The value of the minutes in the left-hand column
is found to be 25,,. Therefore, angle A = 10,, 25'
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