Use “The Chart” to remember these values.

2. Use “The Chart” to remember these values.

3. These terms are interchangeable Example 1 The question this problem is asking is “What is the angle measure of the right triangle that has the side opposite angle x as and the hypotenuse is 2.” The question this problem is asking is “What is the angle measure of the right triangle that has the side adjacent angle x as and the hypotenuse is 2.” To get x alone, multiply by the inverse of sine: To get x alone, multiply by the inverse of cos: arcsin arcsin arccos arccos (calculator or chart) (calculator or chart) This is only the possibility for the 2nd quadrant. According to the table, 225° is also a possibility, along with any coterminal angles. This is only the possibility for the 1st quadrant. According to the table, 120° is also a possibility, along with any coterminal angles.

4. It helps to set the expression equal to x Example 2 What happens when something is multiplied by its inverse? They cancel each other out.

5. Each trig function must always be followed by an angle, Multiply both sides by sin So . . . r = 3, y = 2 Draw a picture w/ this info: Cosine uses the adjacent side, so calculate it:

6. d = 32 (hyp) f = 17 (adj) Example 3 Which trig function?

7. 100 ft 20 ft Be careful not to calculate this angle! Example 4 Angle of Depression has to be formed by a horizontal line.

8. 33° 5.8 Example 5 To solve a triangle means to find all the missing pieces; 3 angles & 3 sides

9. (hyp) 45 23 (opp)

10. HW: Page 309