Lesson 1.3 Rt. Trigonometry (continued) Sin = opp/hyp Cos = - PowerPoint PPT Presentation

Lesson 1.3 Rt.  Trigonometry (continued) Sin  = opp/hyp Cos  = adj/hyp Opposite Side Tan  = opp/adj  Adjacent Side Csc  = hyp/opp Sec  = hyp/adj Cot  = adj/opp

Ex 4: Use the given function value(s), and trig identities (including the co-function identities) to find the indicated trig function. A. sin 60º =  3/2, 2 cos 60º = 1/2 √3 = opp/adj = √3 1.) tan 60º 60° = cos 60° = 1/2 2.) sin 30º 1 (cofunctions) 3.) cos 30º = sin 60° = √3/2 (cofunctions) 4.) cot 30º = tan 60° = √3 (cofunctions)

Ex 4 (continued): Use the given function value(s), and trig identities (including the co- function identities) to find the indicated trig function. 3 √8 B. cos  = 1/3 =2√2  1 1.) sec  = 3/1 = 3 2.) sin  = 2√2/3 3.) cot  = 1/2√2 = √2/4 4.) sin(90 -  ) = cos  = 1/3 (cofunctions)

Ex 5: Evaluate the trig function by memory or constructing an appropriate triangle for the given special angle. 2   1 C. sin 45º A. cos 60º 2 2  1 1 D. cot 45º  B. csc 30º  sin 30 Cofunctions  1  2 1 2 Homework: p.156 #18-28 even