1. Trigonometry Section 4.2 Trigonometric Functions: The Unit Circle

2. Definitions of Trig Functions on Unit Circle Sin t Sin t Cos t Cos t Tan t Tan t Csc t Csc t Sec t Sec t Cot t Cot t These are only true when r=1; we will generalize to any radius r in section 4.4. These are only true when r=1; we will generalize to any radius r in section 4.4.

3. ASTC on Unit Circle ASTC is an acronym that stands for _____________________. ASTC is an acronym that stands for _____________________. A means that all of the basic trigonometric functions are positive in quadrant _____. A means that all of the basic trigonometric functions are positive in quadrant _____. S means that only the sine and the _____ are positive in quadrant _____. S means that only the sine and the _____ are positive in quadrant _____. T means that only the tangent and the _____ are positive in quadrant _____. T means that only the tangent and the _____ are positive in quadrant _____. C means that only the cosine and the _____ are positive in quadrant _____. C means that only the cosine and the _____ are positive in quadrant _____.

4. Periodic, Even, Odd Functions A function is periodic is it repeats for a length c. This length c is called the period. A function is periodic is it repeats for a length c. This length c is called the period. The basic trigonometric functions are _____. The basic trigonometric functions are _____. An even function has _____ symmetry. An even function has _____ symmetry. An odd function has _____ symmetry. An odd function has _____ symmetry. Cosine is an _____ function. Cosine is an _____ function. Sine and tangent are _____ functions. Sine and tangent are _____ functions.

5. Evaluate the Trig Functions Ex 1 Ex 1 If the sin (t)=3/5, what is the sin(-t)=? If the sin (t)=3/5, what is the sin(-t)=? If the cos (t)=3/5, what is the cos(-t)=? If the cos (t)=3/5, what is the cos(-t)=? If the tan(-t)= -10, what is the tan(t)=? If the tan(-t)= -10, what is the tan(t)=?

6. CAUTION When working out problems, check whether your calculator is in radian or degree mode!!! When working out problems, check whether your calculator is in radian or degree mode!!!

7. Homework 1-52 1-52