ENGR 127 Spatial Analysis – Basic Trigonometry Worksheet 1. Reference Triangle l
y 
x
2. For the reference triangle SohCahToa Function Definition for Function Definition for Reference Triangle Reference Triangle Sine: cosecant: sin(A) csc(A) Cosine: cos(A) Tangent: tan(A) secant: sin
cos
1
sin
1
cos
sec(A) cotangent: cot(A) 1
tan
3. Radians and Degrees – How do you convert degrees to radians? Illustrate your procedure by converting 100o to radians. 4. Fill in the exact values for each of these cases. y
sin (0o) =
sin (90o) =
cos (0o) =
o
cos (90 ) =
x
sin (180o) =
sin (- 90o) =
cos (180o) =
cos (- 90o) =
y
o
sin (135 ) =
sin (45o) =
cos (135o) =
cos (45o) =
x
sin (-135o) =
sin (-45o) =
o
cos (-135 ) =
cos (-45o) =
5. Notice values for common angles in Table 3.1 (p. 64) 6. Inverse trig functions: Given a function value, what is the angle? function EXCEL limited range arccosine acos() 0   arcsine, arctan asin(), atan() ‐/2  /2 Special arctan fn. atan2(x,y) ‐    They all have limited ranges. Why?