## 4.1 Introduction • Most computers do calculations in radians ### 4.1.1 Functions

• The basic trigonometry functions are, • Graphs of these functions are given below,      ### 4.1.2 Inverse Functions

• Inverse Functions  • Note: trig calculations can take a while and should be minimized or avoided in programs.

• Scilab example, ### 4.1.3 Triangles

• NOTE: Keep in mind when finding these trig values, that any value that does not lie in the right hand quadrants of cartesian space, may need additions of ±90° or ±180°. ### 4.1.4 Relationships

• Now a group of trigonometric relationships will be given. These are often best used when attempting to manipulate equations. • Scilab for trig identities, • These can also be related to complex exponents, ### 4.1.5 Hyperbolic Functions

• The basic definitions are given below, • some of the basic relationships are, • Some of the more advanced relationships are, • Some of the relationships between the hyperbolic, and normal trigonometry functions are, ### 4.1.6 Special Relationships

• The Small Angle Approximation ### 4.1.7 Planes, Lines, etc.

• The most fundamental mathematical geometry is a line. The basic relationships are given below, • If we assume a line is between two points in space, and that at one end we have a local reference frame, there are some basic relationships that can be derived. • The relationships for a plane are, 