Page 37 - Rotating Machinery Pratical Solutions to Unbalance and Misalignment
P. 37
Developing the Vibration Equations
Figure 2-3. Developing the Cosine Function
R
Y
α
X
For the angle α
X = R Cos α
Y = R Sin α
Figure 2-4. Sine and Cosine Functions
Example of the Sine and Cosine Functions
Now that the first two basic trigonometric functions have
been defined, it is useful to examine a practical use for these func-
tions.
Example 2.1
If a 20-foot ladder were leaned against a building so that its
base was 10 feet from the building, how far up the building would
the ladder reach?
